Can you insert videos in HTML5?

Previously, viewing YouTube videos on a personal computer required the Adobe Flash Player plug-in to be installed in the browser. In January 2010, YouTube launched an experimental version of the site that used the built-in multimedia capabilities of web browsers supporting the HTML5 standard. This allowed videos to be viewed without requiring Adobe Flash Player or any other plug-in to be installed. The YouTube site had a page that allowed supported browsers to opt into the HTML5 trial. Only browsers that supported HTML5 Video using the MP4 (with H.264 video) or WebM (with VP8 video) formats could play the videos, and not all videos on the site were available.

YouTube

YouTube, LLC is an American video-sharing website headquartered in San Bruno, California. Three former PayPal employees—Chad Hurley, Steve Chen, and Jawed Karim—created the service in February 2005. Google bought the site in November 2006 for US$1.65 billion; YouTube now operates as one of Google's subsidiaries.

YouTube allows users to upload, view, rate, share, add to favorites, report, comment on videos, and subscribe to other users. It offers a wide variety of user-generated and corporate media videos. Available content includes video clips, TV show clips, music videos, short and documentary films, audio recordings, movie trailers, live streams, and other content such as video blogging, short original videos, and educational videos. Most of the content on YouTube is uploaded by individuals, but media corporations including CBS, the BBC, Vevo, and Hulu offer some of their material via YouTube as part of the YouTube partnership program. Unregistered users can only watch videos on the site, while registered users are permitted to upload an unlimited number of videos and add comments to videos. Videos deemed potentially inappropriate are available only to registered users affirming themselves to be at least 18 years old.

YouTube earns advertising revenue from Google AdSense, a program which targets ads according to site content and audience. The vast majority of its videos are free to view, but there are exceptions, including subscription-based premium channels, film rentals, as well as YouTube Premium, a subscription service offering ad-free access to the website and access to exclusive content made in partnership with existing users.

, there were more than 400 hours of content uploaded to YouTube each minute, and one billion hours of content being watched on YouTube every day., the website is ranked as the second-most popular site in the world, according to Alexa Internet.

YouTube was founded by Chad Hurley, Steve Chen, and Jawed Karim, who were all early employees of PayPal. Hurley had studied design at Indiana University of Pennsylvania, and Chen and Karim studied computer science together at the University of Illinois at Urbana–Champaign. According to a story that has often been repeated in the media, Hurley and Chen developed the idea for YouTube during the early months of 2005, after they had experienced difficulty sharing videos that had been shot at a dinner party at Chen's apartment in San Francisco. Karim did not attend the party and denied that it had occurred, but Chen commented that the idea that YouTube was founded after a dinner party "was probably very strengthened by marketing ideas around creating a story that was very digestible".

Karim said the inspiration for YouTube first came from Janet Jackson's role in the 2004 Super Bowl incident, when her breast was exposed during her performance, and later from the 2004 Indian Ocean tsunami. Karim could not easily find video clips of either event online, which led to the idea of a video sharing site. Hurley and Chen said that the original idea for YouTube was a video version of an online dating service, and had been influenced by the website Hot or Not.
YouTube began as a venture capital-funded technology startup, primarily from an $11.5 million investment by Sequoia Capital and an $8 million investment from Artis Capital Management between November 2005 and April 2006. YouTube's early headquarters were situated above a pizzeria and Japanese restaurant in San Mateo, California. The domain name codice_1 was activated on February 14, 2005, and the website was developed over the subsequent months. The first YouTube video, titled "Me at the zoo", shows co-founder Jawed Karim at the San Diego Zoo. The video was uploaded on April 23, 2005, and can still be viewed on the site. YouTube offered the public a beta test of the site in May 2005. The first video to reach one million views was a Nike advertisement featuring Ronaldinho in November 2005. Following a $3.5 million investment from Sequoia Capital in November, the site launched officially on December 15, 2005, by which time the site was receiving 8 million views a day. The site grew rapidly and, in July 2006, the company announced that more than 65,000 new videos were being uploaded every day, and that the site was receiving 100 million video views per day. According to data published by market research company comScore, YouTube is the dominant provider of online video in the United States, with a market share of around 43% and more than 14 billion views of videos in May 2010.

In May 2011, 48 hours of new videos were uploaded to the site every minute, which increased to 60 hours every minute in January 2012, 100 hours every minute in May 2013, 300 hours every minute in November 2014, and 400 hours every minute in February 2017. As of January 2012, the site had 800 million unique users a month. It is estimated that in 2007 YouTube consumed as much bandwidth as the entire Internet in 2000. According to third-party web analytics providers, Alexa and SimilarWeb, YouTube is the second-most visited website in the world, ; SimilarWeb also lists YouTube as the top TV and video website globally, attracting more than 15 billion visitors per month. In October 2006, YouTube moved to a new office in San Bruno, California.

The choice of the name codice_1 led to problems for a similarly named website, codice_3. The site's owner, Universal Tube & Rollform Equipment, filed a lawsuit against YouTube in November 2006 after being regularly overloaded by people looking for YouTube. Universal Tube has since changed the name of its website to codice_4. In October 2006, Google Inc. announced that it had acquired YouTube for $1.65 billion in Google stock, and the deal was finalized on November 13, 2006.

In March 2010, YouTube began free streaming of certain content, including 60 cricket matches of the Indian Premier League. According to YouTube, this was the first worldwide free online broadcast of a major sporting event. On March 31, 2010, the YouTube website launched a new design, with the aim of simplifying the interface and increasing the time users spend on the site. Google product manager Shiva Rajaraman commented: "We really felt like we needed to step back and remove the clutter." In May 2010, YouTube videos were watched more than two billion times per day. This increased to three billion in May 2011, and four billion in January 2012. In February 2017, one billion hours of YouTube was watched every day.

In October 2010, Hurley announced that he would be stepping down as chief executive officer of YouTube to take an advisory role, and that Salar Kamangar would take over as head of the company. In April 2011, James Zern, a YouTube software engineer, revealed that 30% of videos accounted for 99% of views on the site. In November 2011, the Google+ social networking site was integrated directly with YouTube and the Chrome web browser, allowing YouTube videos to be viewed from within the Google+ interface.
In December 2011, YouTube launched a new version of the site interface, with the video channels displayed in a central column on the home page, similar to the news feeds of social networking sites. At the same time, a new version of the YouTube logo was introduced with a darker shade of red, the first change in design since October 2006. In May 2013, YouTube launched a pilot program for content providers to offer premium, subscription-based channels within the platform. In February 2014, Susan Wojcicki was appointed CEO of YouTube. In November 2014, YouTube announced a subscription service known as "Music Key", which bundled ad-free streaming of music content on YouTube with the existing Google Play Music service.

In February 2015, YouTube released a secondary mobile app known as YouTube Kids. The app is designed to provide an experience optimized for children. It features a simplified user interface, curated selections of channels featuring age-appropriate content, and parental control features. Later on August 26, 2015, YouTube launched YouTube Gaming—a video gaming-oriented vertical and app for videos and live streaming, intended to compete with the Amazon.com-owned Twitch.

In October 2015, YouTube announced YouTube Red (now Youtube Premium), a new premium service that would offer ad-free access to all content on the platform (succeeding the Music Key service released the previous year), premium original series and films produced by YouTube personalities, as well as background playback of content on mobile devices. YouTube also released YouTube Music, a third app oriented towards streaming and discovering the music content hosted on the YouTube platform.

In January 2016, YouTube expanded its headquarters in San Bruno by purchasing an office park for $215 million. The complex has 554,000 square feet of space and can house up to 2,800 employees.

On August 29, 2017, YouTube officially launched a redesign of its user interfaces based on Material Design language, as well a redesigned logo that is built around the service's play button emblem.

On April 3, 2018, a shooting took place at YouTube's headquarters in San Bruno, California.

On May 17, 2018, YouTube announced the re-branding of YouTube Red as YouTube Premium (accompanied by a major expansion of the service into Canada and 13 European markets), as well as the upcoming launch of a separate YouTube Music subscription.

In September 2018, YouTube began to phase out the separate YouTube Gaming website and app, and introduced a new Gaming portal within the main service. YouTube staff argued that the separate platform was causing confusion, and that the integration would allow the features developed for the service (including game-based portals and enhanced discoverability of gaming-related videos and live streaming) to reach a broader audience through the main YouTube website.

YouTube primarily uses the VP9 and H.264/MPEG-4 AVC video formats, and the Dynamic Adaptive Streaming over HTTP protocol. YouTube has begun rolling out videos in AV1 format.

On January 27, 2015, YouTube announced that HTML5 would be the default playback method on supported browsers. YouTube used to employ Adobe Dynamic Streaming for Flash, but with the switch to HTML5 video now streams video using Dynamic Adaptive Streaming over HTTP (MPEG-DASH), an adaptive bit-rate HTTP-based streaming solution optimizing the bitrate and quality for the available network.

All YouTube users can upload videos up to 15 minutes each in duration. Users who have a good track record of complying with the site's Community Guidelines may be offered the ability to upload videos up to 12 hours in length, as well as live streams, which requires verifying the account, normally through a mobile phone. When YouTube was launched in 2005, it was possible to upload longer videos, but a ten-minute limit was introduced in March 2006 after YouTube found that the majority of videos exceeding this length were unauthorized uploads of television shows and films. The 10-minute limit was increased to 15 minutes in July 2010. In the past, it was possible to upload videos longer than 12 hours. Videos can be at most 128 GB in size. Video captions are made using speech recognition technology when uploaded. Such captioning is usually not perfectly accurate, so YouTube provides several options for manually entering the captions for greater accuracy.

YouTube accepts videos that are uploaded in most container formats, including AVI, MP4, MPEG-PS, QuickTime File Format and FLV. It supports WebM files and also 3GP, allowing videos to be uploaded from mobile phones.

Videos with progressive scanning or interlaced scanning can be uploaded, but for the best video quality, YouTube suggests interlaced videos be deinterlaced before uploading. All the video formats on YouTube use progressive scanning. YouTube's statistics shows that interlaced videos are still being uploaded to YouTube, and there is no sign of that actually dwindling. YouTube attributes this to uploading of made-for-TV content.

YouTube originally offered videos at only one quality level, displayed at a resolution of 320×240 pixels using the Sorenson Spark codec (a variant of H.263), with mono MP3 audio. In June 2007, YouTube added an option to watch videos in 3GP format on mobile phones. In March 2008, a high-quality mode was added, which increased the resolution to 480×360 pixels. In December 2008, 720p HD support was added. At the time of the 720p launch, the YouTube player was changed from a aspect ratio to a widescreen. With this new feature, YouTube began a switchover to H.264/MPEG-4 AVC as its default video compression format. In November 2009, 1080p HD support was added. In July 2010, YouTube announced that it had launched a range of videos in 4K format, which allows a resolution of up to 4096×3072 pixels. In June 2015, support for 8K resolution was added, with the videos playing at 7680×4320 pixels. In November 2016, support for HDR video was added which can be encoded with Hybrid Log-Gamma (HLG) or Perceptual Quantizer (PQ). HDR video can be encoded with the Rec. 2020 color space.

In October 2014, YouTube introduced videos playing at 60 frames per second, in order to reproduce video games with a frame rate comparable to high-end graphics cards. The videos play back at a resolution of 720p or higher. YouTube videos are available in a range of quality levels. The former names of standard quality (SQ), high quality (HQ), and high definition (HD) have been replaced by numerical values representing the vertical resolution of the video. The default video stream is encoded in the VP9 format with stereo Opus audio; if VP9/WebM is not supported in the browser/device or the browser's user agent reports Windows XP, then H.264/MPEG-4 AVC video with stereo AAC audio is used instead.

From 2008 to 2017, users could add "annotations" to their videos—such as pop-up text messages and hyperlinks. These functions were notably used as the basis for interactive videos, which used hyperlinks to other videos to achieve branching elements. In March 2017, it was announced that the annotations editor had been discontinued and the feature would be sunset, because their use had fallen rapidly, users had found them to be an annoyance, and because they were incompatible with mobile versions of the service. Annotations will be removed entirely from all videos on January 15, 2019. YouTube had introduced standardized widgets intended to replace annotations in a cross-platform manner, including "end screens" (a customizable array of thumbnails for specified videos displayed near the end of the video) and "cards", but they are not backwards compatible with existing annotations, while the removal of annotations will also break all interactive experiences which depended on them.

YouTube carried out early experiments with live streaming, including a concert by U2 in 2009, and a question-and-answer session with US President Barack Obama in February 2010. These tests had relied on technology from 3rd-party partners, but in September 2010, YouTube began testing its own live streaming infrastructure. In April 2011, YouTube announced the rollout of "YouTube Live", with a portal page at the URL "www.youtube.com/live". The creation of live streams was initially limited to select partners. It was used for real-time broadcasting of events such as the 2012 Olympics in London. In October 2012, more than 8 million people watched Felix Baumgartner's jump from the edge of space as a live stream on YouTube.

In May 2013, creation of live streams was opened to verified users with at least 1,000 subscribers; in August of that year the number was reduced to 100 subscribers, and in December the limit was removed. In February 2017, live streaming was introduced to the official YouTube mobile app. Live streaming via mobile was initially restricted to users with at least 10,000 subscribers, but as of mid-2017 it has been reduced to 100 subscribers. Live streams can be up to 4K resolution at 60 fps, and also support 360° video. In February 2017, a live streaming feature called Super Chat was introduced, which allows viewers to donate between $1 and $500 to have their comment highlighted.

In a video posted on July 21, 2009, YouTube software engineer Peter Bradshaw announced that YouTube users could now upload 3D videos. The videos can be viewed in several different ways, including the common anaglyph (cyan/red lens) method which utilizes glasses worn by the viewer to achieve the 3D effect. The YouTube Flash player can display stereoscopic content interleaved in rows, columns or a checkerboard pattern, side-by-side or anaglyph using a red/cyan, green/magenta or blue/yellow combination. In May 2011, an HTML5 version of the YouTube player began supporting side-by-side 3D footage that is compatible with Nvidia 3D Vision. The feature set has since been reduced, and the 3D feature currently only supports red/cyan anaglyph with no side-by-side support.

In January 2015, Google announced that 360-degree video would be natively supported on YouTube. On March 13, 2015, YouTube enabled 360° videos which can be viewed from Google Cardboard, a virtual reality system. YouTube 360 can also be viewed from all other virtual reality headsets. Live streaming of 360° video at up to 4K resolution is also supported.

In 2017, YouTube began to promote an alternative stereoscopic video format known as VR180, which is limited to a 180-degree field of view, but is promoted as being easier to produce than 360-degree video, and allowing more depth to be maintained by not subjecting the video to equirectangular projection.

In late November 2018, YouTube announced that it would introduce a "Story" feature, similar to ones used by Snapchat and Instagram, which would allow its content creators to engage fans without posting a full video. The stories, called "Reels," would be up to 30 seconds in length and would allow users to add "filters, music, text and more, including new "YouTube-y" stickers." Unlike those of other platforms, YouTube's stories could be made multiple times and would not expire. Instead of being placed at the top of the user interface as is commonly done, the "Reels" option would be featured as a separate tab on the creator's channel. As of its announcement, only certain content creators would have access to the "Reels" option, which would be utilized as a beta-version for further feedback and testing. If users engage more with the "Reels" option, it may end up as a more permanent feature and "trigger their appearance on the viewer's YouTube home page as recommendations." As of November 28, 2018, Youtube did not specify when "Reels" would arrive in Beta or when it would be publicly released.

On September 13, 2016, YouTube launched a public beta of Community, a social media-based feature that allows users to post text, images (including GIFs), live videos and others in a separate "Community" tab on their channel. Prior to the release, several creators had been consulted to suggest tools Community could incorporate that they would find useful; these YouTubers included Vlogbrothers, AsapScience, Lilly Singh, The Game Theorists, Karmin, The Key of Awesome, The Kloons, Peter Hollens, Rosianna Halse Rojas, Sam Tsui, Threadbanger and Vsauce3.

YouTube offers users the ability to view its videos on web pages outside their website. Each YouTube video is accompanied by a piece of HTML that can be used to embed it on any page on the Web. This functionality is often used to embed YouTube videos in social networking pages and blogs. Users wishing to post a video discussing, inspired by or related to another user's video are able to make a "video response". On August 27, 2013, YouTube announced that it would remove video responses for being an underused feature. Embedding, rating, commenting and response posting can be disabled by the video owner.

YouTube does not usually offer a download link for its videos, and intends for them to be viewed through its website interface. A small number of videos, can be downloaded as MP4 files. Numerous third-party web sites, applications and browser plug-ins allow users to download YouTube videos. In February 2009, YouTube announced a test service, allowing some partners to offer video downloads for free or for a fee paid through Google Checkout. In June 2012, Google sent cease and desist letters threatening legal action against several websites offering online download and conversion of YouTube videos. In response, Zamzar removed the ability to download YouTube videos from its site.

Users retain copyright of their own work, but have the option to grant certain usage rights under any public copyright license they choose. Since July 2012, it has been possible to select a Creative Commons license as the default, allowing other users to reuse and remix the material.

Most modern smartphones are capable of accessing YouTube videos, either within an application or through an optimized website. YouTube Mobile was launched in June 2007, using RTSP streaming for the video. Not all of YouTube's videos are available on the mobile version of the site. Since June 2007, YouTube's videos have been available for viewing on a range of Apple products. This required YouTube's content to be transcoded into Apple's preferred video standard, H.264, a process that took several months. YouTube videos can be viewed on devices including Apple TV, iPod Touch and the iPhone. In July 2010, the mobile version of the site was relaunched based on HTML5, avoiding the need to use Adobe Flash Player and optimized for use with touch screen controls. The mobile version is also available as an app for the Android platform. In September 2012, YouTube launched its first app for the iPhone, following the decision to drop YouTube as one of the preloaded apps in the iPhone 5 and iOS 6 operating system. According to GlobalWebIndex, YouTube was used by 35% of smartphone users between April and June 2013, making it the third-most used app.

A TiVo service update in July 2008 allowed the system to search and play YouTube videos. In January 2009, YouTube launched "YouTube for TV", a version of the website tailored for set-top boxes and other TV-based media devices with web browsers, initially allowing its videos to be viewed on the PlayStation 3 and Wii video game consoles. In June 2009, YouTube XL was introduced, which has a simplified interface designed for viewing on a standard television screen. YouTube is also available as an app on Xbox Live. On November 15, 2012, Google launched an official app for the Wii, allowing users to watch YouTube videos from the Wii channel. An app is also available for Wii U and Nintendo 3DS, and videos can be viewed on the Wii U Internet Browser using HTML5. Google made YouTube available on the Roku player on December 17, 2013, and, in October 2014, the Sony PlayStation 4. In November 2018, YouTube launched as a downloadable app for the Nintendo Switch.

On June 19, 2007, Google CEO Eric Schmidt traveled to Paris to launch the new localization system. The interface of the website is available with localized versions in 98 countries, one territory (Hong Kong) and a worldwide version.

The YouTube interface suggests which local version should be chosen on the basis of the IP address of the user. In some cases, the message "This video is not available in your country" may appear because of copyright restrictions or inappropriate content. The interface of the YouTube website is available in 76 language versions, including Amharic, Albanian, Armenian, Bengali, Burmese, Khmer, Kyrgyz, Laotian, Mongolian, Persian and Uzbek, which do not have local channel versions. Access to YouTube was blocked in Turkey between 2008 and 2010, following controversy over the posting of videos deemed insulting to Mustafa Kemal Atatürk and some material offensive to Muslims. In October 2012, a local version of YouTube was launched in Turkey, with the domain codice_5. The local version is subject to the content regulations found in Turkish law. In March 2009, a dispute between YouTube and the British royalty collection agency PRS for Music led to premium music videos being blocked for YouTube users in the United Kingdom. The removal of videos posted by the major record companies occurred after failure to reach agreement on a licensing deal. The dispute was resolved in September 2009. In April 2009, a similar dispute led to the removal of premium music videos for users in Germany.

YouTube Premium (formerly YouTube Red) is YouTube's premium subscription service. It offers advertising-free streaming, access to exclusive content, background and offline video playback on mobile devices, and access to the Google Play Music "All Access" service. YouTube Premium was originally announced on November 12, 2014, as "Music Key", a subscription music streaming service, and was intended to integrate with and replace the existing Google Play Music "All Access" service. On October 28, 2015, the service was relaunched as YouTube Red, offering ad-free streaming of all videos, as well as access to exclusive original content., the service has 1.5 million subscribers, with a further million on a free-trial basis., the first season of YouTube Red Originals had gotten 250 million views in total.

In May 2014, before Music Key service was launched, the independent music trade organization Worldwide Independent Network alleged that YouTube was using non-negotiable contracts with independent labels that were "undervalued" in comparison to other streaming services, and that YouTube would block all music content from labels who do not reach a deal to be included on the paid service. In a statement to the "Financial Times" in June 2014, Robert Kyncl confirmed that YouTube would block the content of labels who do not negotiate deals to be included in the paid service "to ensure that all content on the platform is governed by its new contractual terms." Stating that 90% of labels had reached deals, he went on to say that "while we wish that we had [a] 100% success rate, we understand that is not likely an achievable goal and therefore it is our responsibility to our users and the industry to launch the enhanced music experience." The "Financial Times" later reported that YouTube had reached an aggregate deal with Merlin Network—a trade group representing over 20,000 independent labels, for their inclusion in the service. However, YouTube itself has not confirmed the deal.

On September 28, 2016, YouTube named Lyor Cohen, the co-founder of 300 Entertainment and former Warner Music Group executive, the Global Head of Music.

On February 28, 2017, in a press announcement held at YouTube Space Los Angeles, YouTube announced the launch of YouTube TV, an over-the-top MVPD-style subscription service that would be available for United States customers at a price of US$35 per month. Initially launching in five major markets (New York City, Los Angeles, Chicago, Philadelphia and San Francisco) on April 5, 2017, the service offers live streams of programming from the five major broadcast networks (ABC, CBS, The CW, Fox and NBC), as well as approximately 40 cable channels owned by the corporate parents of those networks, The Walt Disney Company, CBS Corporation, 21st Century Fox, NBCUniversal and Turner Broadcasting System (including among others Bravo, USA Network, Syfy, Disney Channel, CNN, Cartoon Network, E!, Fox Sports 1, Freeform, FX and ESPN). Subscribers can also receive Showtime and Fox Soccer Plus as optional add-ons for an extra fee, and can access YouTube Premium original content (YouTube TV does not include a YouTube Red subscription).

During the 2017 World Series (in which it was the presenting sponsor), YouTube TV ads were placed behind the home plate. The trademarked red play button logo appeared at the center of the screen, mimicking YouTube's interface.

YouTube Go is an Android app aimed at making YouTube easier to access on mobile devices in emerging markets. It is distinct from the company's main Android app and allows videos to be downloaded and shared with other users. It also allows users to preview videos, share downloaded videos through Bluetooth, and offers more options for mobile data control and video resolution.

YouTube announced the project in September 2016 at an event in India. It was launched in India in February 2017, and expanded in November 2017 to 14 other countries, including Nigeria, Indonesia, Thailand, Malaysia, Vietnam, the Philippines, Kenya, and South Africa. It was rolled out in 130 countries worldwide, including Brazil, Mexico, Turkey, and Iraq on February 1, 2018. The app is available to around 60% of the world's population.

In early 2018, Cohen began hinting at the possible launch of YouTube's new subscription music streaming service, a platform that would compete with other services such as Spotify and Apple Music. On May 22, 2018, the music streaming platform named "YouTube Music" was launched.

In 2018, YouTube became an ISNI registry, and announced its intention to begin creating ISNI identifiers to uniquely identify the musicians whose videos it features. ISNI anticipate the number of ISNI IDs "going up by perhaps 3-5 million over the next couple of years" as a result.

YouTube featured an April Fools prank on the site on April 1 of every year from 2008 to 2016. In 2008, all links to videos on the main page were redirected to Rick Astley's music video "Never Gonna Give You Up", a prank known as "rickrolling". The next year, when clicking on a video on the main page, the whole page turned upside down, which YouTube claimed was a "new layout". In 2010, YouTube temporarily released a "TEXTp" mode which transformed colors in videos to random uppercase letters "in order to reduce bandwidth costs by $1 per second." The next year, the site celebrated its "100th anniversary" with a range of sepia-toned silent, early 1900s-style films, including a parody of Keyboard Cat. In 2012, clicking on the image of a DVD next to the site logo led to a video about a purported option to order every YouTube video for home delivery on DVD. In 2013, YouTube teamed up with satirical newspaper company "The Onion" to claim that the video sharing website was launched as a contest which had finally come to an end, and would announce a winner of the contest when the site went back up in 2023. In 2014, YouTube announced that it was responsible for the creation of all viral video trends, and revealed previews of upcoming internet memes, such as "Clocking", "Kissing Dad", and "Glub Glub Water Dance". The next year, YouTube added a music button to the video bar that played samples from "Sandstorm" by Darude. In 2016, YouTube introduced an option to watch every video on the platform in 360-degree mode with Snoop Dogg.

In 2016, YouTube introduced a global program to develop creators whose videos produce a positive social impact. Google dedicated $1 million to the this Creators for Change program. The first three videos from the program premiered at the 2017 Tribeca TV Festival. YouTube expanded the program in 2018.

Both private individuals and large production companies have used YouTube to grow audiences. Independent content creators have built grassroots followings numbering in the thousands at very little cost or effort, while mass retail and radio promotion proved problematic. Concurrently, old media celebrities moved into the website at the invitation of a YouTube management that witnessed early content creators accruing substantial followings, and perceived audience sizes potentially larger than that attainable by television. While YouTube's revenue-sharing "Partner Program" made it possible to earn a substantial living as a video producer—its top five hundred partners each earning more than $100,000 annually and its ten highest-earning channels grossing from $2.5 million to $12 million—in 2012 CMU business editor characterized YouTube as "a free-to-use... promotional platform for the music labels". In 2013 "Forbes" Katheryn Thayer asserted that digital-era artists' work must not only be of high quality, but must elicit reactions on the YouTube platform and social media. Videos of the 2.5% of artists categorized as "mega", "mainstream" and "mid-sized" received 90.3% of the relevant views on YouTube and Vevo in that year. By early 2013 "Billboard" had announced that it was factoring YouTube streaming data into calculation of the "Billboard" Hot 100 and related genre charts.

Observing that face-to-face communication of the type that online videos convey has been "fine-tuned by millions of years of evolution", TED curator Chris Anderson referred to several YouTube contributors and asserted that "what Gutenberg did for writing, online video can now do for face-to-face communication". Anderson asserted that it's not far-fetched to say that online video will dramatically accelerate scientific advance, and that video contributors may be about to launch "the biggest learning cycle in human history." In education, for example, the Khan Academy grew from YouTube video tutoring sessions for founder Salman Khan's cousin into what "Forbes"  Michael Noer called "the largest school in the world", with technology poised to disrupt how people learn. YouTube was awarded a 2008 George Foster Peabody Award, the website being described as a Speakers' Corner that "both embodies and promotes democracy." "The Washington Post" reported that a disproportionate share of YouTube's most subscribed channels feature minorities, contrasting with mainstream television in which the stars are largely white. A Pew Research Center study reported the development of "visual journalism", in which citizen eyewitnesses and established news organizations share in content creation. The study also concluded that YouTube was becoming an important platform by which people acquire news.

YouTube has enabled people to more directly engage with government, such as in the CNN/YouTube presidential debates (2007) in which ordinary people submitted questions to U.S. presidential candidates via YouTube video, with a techPresident co-founder saying that Internet video was changing the political landscape. Describing the Arab Spring (2010– ), sociologist Philip N. Howard quoted an activist's succinct description that organizing the political unrest involved using "Facebook to schedule the protests, Twitter to coordinate, and YouTube to tell the world." In 2012, more than a third of the U.S. Senate introduced a resolution condemning Joseph Kony 16 days after the "Kony 2012" video was posted to YouTube, with resolution co-sponsor Senator Lindsey Graham remarking that the video "will do more to lead to (Kony's) demise than all other action combined."
Conversely, YouTube has also allowed government to more easily engage with citizens, the White House's official YouTube channel being the seventh top news organization producer on YouTube in 2012 and in 2013 a healthcare exchange commissioned Obama impersonator Iman Crosson's YouTube music video spoof to encourage young Americans to enroll in the Affordable Care Act (Obamacare)-compliant health insurance. In February 2014, U.S. President Obama held a meeting at the White House with leading YouTube content creators to not only promote awareness of Obamacare but more generally to develop ways for government to better connect with the "YouTube Generation". Whereas YouTube's inherent ability to allow presidents to directly connect with average citizens was noted, the YouTube content creators' new media savvy was perceived necessary to better cope with the website's distracting content and fickle audience.

Some YouTube videos have themselves had a direct effect on world events, such as "Innocence of Muslims" (2012) which spurred protests and related anti-American violence internationally. TED curator Chris Anderson described a phenomenon by which geographically distributed individuals in a certain field share their independently developed skills in YouTube videos, thus challenging others to improve their own skills, and spurring invention and evolution in that field. Journalist Virginia Heffernan stated in "The New York Times" that such videos have "surprising implications" for the dissemination of culture and even the future of classical music.

"The Legion of Extraordinary Dancers" and the YouTube Symphony Orchestra selected their membership based on individual video performances. Further, the cybercollaboration charity video "We Are the World 25 for Haiti (YouTube edition)" was formed by mixing performances of 57 globally distributed singers into a single musical work, with "The Tokyo Times" noting the "We Pray for You" YouTube cyber-collaboration video as an example of a trend to use crowdsourcing for charitable purposes.
The anti-bullying It Gets Better Project expanded from a single YouTube video directed to discouraged or suicidal LGBT teens, that within two months drew video responses from hundreds including U.S. President Barack Obama, Vice President Biden, White House staff, and several cabinet secretaries. Similarly, in response to fifteen-year-old Amanda Todd's video "My story: Struggling, bullying, suicide, self-harm", legislative action was undertaken almost immediately after her suicide to study the prevalence of bullying and form a national anti-bullying strategy. In May 2018, London Metropolitan Police claimed that the drill videos that talk about violence give rise to the gang-related violence. YouTube deleted 30 music videos after the complaint.

Google does not provide detailed figures for YouTube's running costs, and YouTube's revenues in 2007 were noted as "not material" in a regulatory filing. In June 2008, a "Forbes" magazine article projected the 2008 revenue at $200 million, noting progress in advertising sales. In January 2012, it was estimated that visitors to YouTube spent an average of 15 minutes a day on the site, in contrast to the four or five hours a day spent by a typical US citizen watching television. In 2012, YouTube's revenue from its ads program was estimated at $3.7 billion. In 2013 it nearly doubled and estimated to hit $5.6 billion according to eMarketer, while others estimated $4.7 billion. The vast majority of videos on YouTube are free to view and supported by advertising. In May 2013, YouTube introduced a trial scheme of 53 subscription channels with prices ranging from $0.99 to $6.99 a month. The move was seen as an attempt to compete with other providers of online subscription services such as Netflix and Hulu. In 2017, viewers on average watch YouTube on mobile devices for more than an hour every day.

YouTube entered into a marketing and advertising partnership with NBC in June 2006. In March 2007, it struck a deal with BBC for three channels with BBC content, one for news and two for entertainment. In November 2008, YouTube reached an agreement with MGM, Lions Gate Entertainment, and CBS, allowing the companies to post full-length films and television episodes on the site, accompanied by advertisements in a section for U.S. viewers called "Shows". The move was intended to create competition with websites such as Hulu, which features material from NBC, Fox, and Disney. In November 2009, YouTube launched a version of "Shows" available to UK viewers, offering around 4,000 full-length shows from more than 60 partners. In January 2010, YouTube introduced an online film rentals service, which is only available to users in the United States, Canada, and the UK as of 2010. The service offers over 6,000 films.

In May 2007, YouTube launched its Partner Program (YPP), a system based on AdSense which allows the uploader of the video to share the revenue produced by advertising on the site. YouTube typically takes 45 percent of the advertising revenue from videos in the Partner Program, with 55 percent going to the uploader.

There are over a million members of the YouTube Partner Program. According to TubeMogul, in 2013 a pre-roll advertisement on YouTube (one that is shown before the video starts) cost advertisers on average $7.60 per 1000 views. Usually no more than half of eligible videos have a pre-roll advertisement, due to a lack of interested advertisers.

In 2013, YouTube introduced an option for channels with at least a thousand subscribers to require a paid subscription in order for viewers to watch videos. In April 2017, YouTube set an eligibility requirement of 10,000 lifetime views for a paid subscription. On January 16, 2018, the eligibility requirement for monetization was changed to 4,000 hours of watchtime within the past 12 months and 1,000 subscribers. The move was seen as an attempt to ensure that videos being monetized did not lead to controversy, but was criticized for penalizing smaller YouTube channels.

YouTube Play Buttons, a part of the YouTube Creator Rewards, are a recognition by YouTube of its most popular channels. The trophies made of nickel plated copper-nickel alloy, golden plated brass, silver plated metal and ruby are given to channels with at least one hundred thousand, a million, ten million and fifty million subscribers, respectively.

Users of the YPP can have their videos "demonetized" if YouTube feels that the content is not advertiser-friendly. If a video receives this status, ad revenue will be canceled for the video in question, and the video will have a yellow coin symbol in the Partner's YouTube dashboard.

Much of YouTube's revenue goes to the copyright holders of the videos. In 2010, it was reported that nearly a third of the videos with advertisements were uploaded without permission of the copyright holders. YouTube gives an option for copyright holders to locate and remove their videos or to have them continue running for revenue. In May 2013, Nintendo began enforcing its copyright ownership and claiming the advertising revenue from video creators who posted screenshots of its games. In February 2015, Nintendo agreed to share the revenue with the video creators.

YouTube has a set of community guidelines aimed to reduce abuse of the site's features. Generally prohibited material includes sexually explicit content, videos of animal abuse, shock videos, content uploaded without the copyright holder's consent, hate speech, spam, and predatory behavior. Despite the guidelines, YouTube has faced criticism from news sources for content in violation of these guidelines.

At the time of uploading a video, YouTube users are shown a message asking them not to violate copyright laws. Despite this advice, there are still many unauthorized clips of copyrighted material on YouTube. YouTube does not view videos before they are posted online, and it is left to copyright holders to issue a DMCA takedown notice pursuant to the terms of the Online Copyright Infringement Liability Limitation Act. Any successful complaint about copyright infringement results in a YouTube copyright strike. Three successful complaints for copyright infringement against a user account will result in the account and all of its uploaded videos being deleted. Organizations including Viacom, Mediaset, and the English Premier League have filed lawsuits against YouTube, claiming that it has done too little to prevent the uploading of copyrighted material. Viacom, demanding $1 billion in damages, said that it had found more than 150,000 unauthorized clips of its material on YouTube that had been viewed "an astounding 1.5 billion times". YouTube responded by stating that it "goes far beyond its legal obligations in assisting content owners to protect their works".

During the same court battle, Viacom won a court ruling requiring YouTube to hand over 12 terabytes of data detailing the viewing habits of every user who has watched videos on the site. The decision was criticized by the Electronic Frontier Foundation, which called the court ruling "a setback to privacy rights". In June 2010, Viacom's lawsuit against Google was rejected in a summary judgment, with U.S. federal Judge Louis L. Stanton stating that Google was protected by provisions of the Digital Millennium Copyright Act. Viacom announced its intention to appeal the ruling. On April 5, 2012, the United States Court of Appeals for the Second Circuit reinstated the case, allowing Viacom's lawsuit against Google to be heard in court again. On March 18, 2014, the lawsuit was settled after seven years with an undisclosed agreement.

In August 2008, a US court ruled in "Lenz v. Universal Music Corp." that copyright holders cannot order the removal of an online file without first determining whether the posting reflected fair use of the material. The case involved Stephanie Lenz from Gallitzin, Pennsylvania, who had made a home video of her 13-month-old son dancing to Prince's song "Let's Go Crazy", and posted the 29-second video on YouTube. In the case of "Smith v. Summit Entertainment LLC", professional singer Matt Smith sued Summit Entertainment for the wrongful use of copyright takedown notices on YouTube. He asserted seven causes of action, and four were ruled in Smith's favor.

In April 2012, a court in Hamburg ruled that YouTube could be held responsible for copyrighted material posted by its users. The performance rights organization GEMA argued that YouTube had not done enough to prevent the uploading of German copyrighted music. YouTube responded by stating:

On November 1, 2016, the dispute with GEMA was resolved, with Google content ID being used to allow advertisements to be added to videos with content protected by GEMA.

In April 2013, it was reported that Universal Music Group and YouTube have a contractual agreement that prevents content blocked on YouTube by a request from UMG from being restored, even if the uploader of the video files a DMCA counter-notice. When a dispute occurs, the uploader of the video has to contact UMG. YouTube's owner Google announced in November 2015 that they would help cover the legal cost in select cases where they believe fair use defenses apply.

In June 2007, YouTube began trials of a system for automatic detection of uploaded videos that infringe copyright. Google CEO Eric Schmidt regarded this system as necessary for resolving lawsuits such as the one from Viacom, which alleged that YouTube profited from content that it did not have the right to distribute. The system, which was initially called "Video Identification" and later became known as Content ID, creates an ID File for copyrighted audio and video material, and stores it in a database. When a video is uploaded, it is checked against the database, and flags the video as a copyright violation if a match is found. When this occurs, the content owner has the choice of blocking the video to make it unviewable, tracking the viewing statistics of the video, or adding advertisements to the video. By 2010, YouTube had "already invested tens of millions of dollars in this technology". In 2011, YouTube described Content ID as "very accurate in finding uploads that look similar to reference files that are of sufficient length and quality to generate an effective ID File". By 2012, Content ID accounted for over a third of the monetized views on YouTube.

An independent test in 2009 uploaded multiple versions of the same song to YouTube, and concluded that while the system was "surprisingly resilient" in finding copyright violations in the audio tracks of videos, it was not infallible. The use of Content ID to remove material automatically has led to controversy in some cases, as the videos have not been checked by a human for fair use. If a YouTube user disagrees with a decision by Content ID, it is possible to fill in a form disputing the decision. Prior to 2016, videos weren't monetized until the dispute was resolved. Since April 2016, videos continue to be monetized while the dispute is in progress, and the money goes to whoever won the dispute. Should the uploader want to monetize the video again, they may remove the disputed audio in the "Video Manager". YouTube has cited the effectiveness of Content ID as one of the reasons why the site's rules were modified in December 2010 to allow some users to upload videos of unlimited length.

YouTube has also faced criticism over the handling of offensive content in some of its videos. The uploading of videos containing defamation, pornography, and material encouraging criminal conduct is forbidden by YouTube's "Community Guidelines". YouTube relies on its users to flag the content of videos as inappropriate, and a YouTube employee will view a flagged video to determine whether it violates the site's guidelines.

Controversial content has included material relating to Holocaust denial and the Hillsborough disaster, in which 96 football fans from Liverpool were crushed to death in 1989. In July 2008, the Culture and Media Committee of the House of Commons of the United Kingdom stated that it was "unimpressed" with YouTube's system for policing its videos, and argued that "proactive review of content should be standard practice for sites hosting user-generated content". YouTube responded by stating:

In October 2010, U.S. Congressman Anthony Weiner urged YouTube to remove from its website videos of imam Anwar al-Awlaki. YouTube pulled some of the videos in November 2010, stating they violated the site's guidelines. In December 2010, YouTube added the ability to flag videos for containing terrorism content.

Following media reports about PRISM, NSA's massive electronic surveillance program, in June 2013, several technology companies were identified as participants, including YouTube. According to leaks of said program, YouTube joined the PRISM program in 2010.

YouTube's policies on "advertiser-friendly content" restrict what may be incorporated into videos being monetized; this includes strong violence, language, sexual content, and "controversial or sensitive subjects and events, including subjects related to war, political conflicts, natural disasters and tragedies, even if graphic imagery is not shown", unless the content is "usually newsworthy or comedic and the creator's intent is to inform or entertain". In September 2016, after introducing an enhanced notification system to inform users of these violations, YouTube's policies were criticized by prominent users, including Phillip DeFranco and Vlogbrothers. DeFranco argued that not being able to earn advertising revenue on such videos was "censorship by a different name". A YouTube spokesperson stated that while the policy itself was not new, the service had "improved the notification and appeal process to ensure better communication to our creators".
In March 2017, the government of the United Kingdom pulled its advertising campaigns from YouTube, after reports that its ads had appeared on videos containing extremism content. The government demanded assurances that its advertising would "be delivered in a safe and appropriate way". "The Guardian" newspaper, as well as other major British and U.S. brands, similarly suspended their advertising on YouTube in response to their advertising appearing near offensive content. Google stated that it had "begun an extensive review of our advertising policies and have made a public commitment to put in place changes that give brands more control over where their ads appear". In early April 2017, the YouTube channel h3h3Productions presented evidence claiming that a "Wall Street Journal" article had fabricated screenshots showing major brand advertising on an offensive video containing Johnny Rebel music overlaid on a Chief Keef music video, citing that the video itself had not earned any ad revenue for the uploader. The video was retracted after it was found that the ads had actually been triggered by the use of copyrighted content in the video.

On April 6, 2017, YouTube announced that in order to "ensure revenue only flows to creators who are playing by the rules", it would change its practices to require that a channel undergo a policy compliance review, and have at least 10,000 lifetime views, before they may join the Partner Program. On January 16, 2018, YouTube announced tighter thresholds where creators must have at least 4,000 hours of watch time within the past 12 months and at least 1,000 subscribers.

In January 2019, YouTube officially banned videos containing "challenges that encourage acts that have an inherent risk of severe physical harm", as well as pranks that "make victims believe they're in physical danger" or cause emotional distress in children, such as the Tide Pod Challenge.

YouTube has been criticized for using an algorithm that gives great prominence to videos that promote conspiracy theories, falsehoods and incendiary fringe discourse. According to an investigation by "The Wall Street Journal", "YouTube’s recommendations often lead users to channels that feature conspiracy theories, partisan viewpoints and misleading videos, even when those users haven’t shown interest in such content. When users show a political bias in what they choose to view, YouTube typically recommends videos that echo those biases, often with more-extreme viewpoints." When users search for political or scientific terms, YouTube's search algorithms often give prominence to hoaxes and conspiracy theories. After YouTube drew controversy for giving top billing to videos promoting falsehoods and conspiracy when people made breaking-news queries during the 2017 Las Vegas shooting, YouTube changed its algorithm to give greater prominence to mainstream media sources. In 2018, it was reported that YouTube was again promoting fringe content about breaking news, giving great prominence to conspiracy videos about Anthony Bourdain's death.

In 2017, it was revealed that advertisements were being placed on extremist videos, including videos by rape apologists, anti-Semites and hate preachers who received ad payouts. After firms started to stop advertising on YouTube in the wake of this reporting, YouTube apologized and said that it would give firms greater control over where ads got placed.

Alex Jones, known for far-right conspiracy theories, has built a massive audience on YouTube. YouTube drew criticism in 2018 when it removed a video from a leftwing watchdog compiling offensive statements made by Jones, claiming that it was "harassment and bullying". On August 6, 2018, however, YouTube removed Alex Jones' YouTube page following a content violation.

University of North Carolina professor Zeynep Tufekci has referred to YouTube as "The Great Radicalizer", saying "YouTube may be one of the most powerful radicalizing instruments of the 21st century." Jonathan Albright of the Tow Center for Digital Journalism at Columbia University described YouTube as a "conspiracy ecosystem".

In January 2019, YouTube said that it had introduced a new policy intended to stop recommending videos containing "content that could misinform users in harmful ways." YouTube gave flat earth theories, miracle cures, and 9/11 trutherism as examples.

In 2017, YouTube was associated with several controversies related to child safety. During Q2, the owners of popular channel DaddyOFive, which featured themselves playing "pranks" on their children, were accused of child abuse. Their videos were eventually deleted, and two of their children were removed from their custody.

Later that year, YouTube came under criticism for showing inappropriate videos targeted at children and often featuring popular characters in violent, sexual or otherwise disturbing situations, many of which appeared on YouTube Kids and attracted millions of views. The term "Elsagate" was coined on the Internet and then used by various news outlets to refer to this controversy. On November 11, 2017, YouTube announced it was strengthening site security to protect children from unsuitable content. Later that month, the company started to mass delete videos and channels that made improper use of family friendly characters. As part as a broader concern regarding child safety on YouTube, the wave of deletions also targeted channels which showed children taking part in inappropriate or dangerous activities under the guidance of adults. Most notably, the company removed "Toy Freaks", a channel with over 8.5 million subscribers, that featured a father and his two daughters in odd and upsetting situations. According to analytics specialist SocialBlade, it earned up to £8.7 million annually prior to its deletion.

Also in November 2017, it was revealed in the media that many videos featuring children – often uploaded by the minors themselves, and showing innocent content – were attracting comments from pedophiles and circulating on the dark web, with predators finding the videos by typing in certain keywords in Russian. As a result of the controversy, which added to the concern about "Elsagate", several major advertisers whose ads had been running against such videos froze spending on YouTube.

Most videos enable users to leave comments, and these have attracted attention for the negative aspects of both their form and content. In 2006, "Time" praised Web 2.0 for enabling "community and collaboration on a scale never seen before", and added that YouTube "harnesses the stupidity of crowds as well as its wisdom. Some of the comments on YouTube make you weep for the future of humanity just for the spelling alone, never mind the obscenity and the naked hatred". "The Guardian" in 2009 described users' comments on YouTube as:

In September 2008, "The Daily Telegraph" commented that YouTube was "notorious" for "some of the most confrontational and ill-formed comment exchanges on the internet", and reported on YouTube Comment Snob, "a new piece of software that blocks rude and illiterate posts". "The Huffington Post" noted in April 2012 that finding comments on YouTube that appear "offensive, stupid and crass" to the "vast majority" of the people is hardly difficult.

On November 6, 2013, Google implemented a comment system oriented on Google+ that required all YouTube users to use a Google+ account in order to comment on videos. The stated motivation for the change was giving creators more power to moderate and block comments, thereby addressing frequent criticisms of their quality and tone. The new system restored the ability to include URLs in comments, which had previously been removed due to problems with abuse. In response, YouTube co-founder Jawed Karim posted the question "why the fuck do I need a google+ account to comment on a video?" on his YouTube channel to express his negative opinion of the change. The official YouTube announcement received 20,097 "thumbs down" votes and generated more than 32,000 comments in two days. Writing in the "Newsday" blog Silicon Island, Chase Melvin noted that "Google+ is nowhere near as popular a social media network as Facebook, but it's essentially being forced upon millions of YouTube users who don't want to lose their ability to comment on videos" and "Discussion forums across the Internet are already bursting with outcry against the new comment system". In the same article Melvin goes on to say:

On July 27, 2015, Google announced in a blog post that it would be removing the requirement to sign up to a Google+ account to post comments to YouTube.

On November 3, 2016, YouTube announced a trial scheme which allows the creators of videos to decide whether to approve, hide or report the comments posted on videos based on an algorithm that detects potentially offensive comments. Creators may also choose to keep or delete comments with links or hashtags in order to combat spam. They can also allow other users to moderate their comments.

In December 2012, two billion views were removed from the view counts of Universal and Sony music videos on YouTube, prompting a claim by "The Daily Dot" that the views had been deleted due to a violation of the site's terms of service, which ban the use of automated processes to inflate view counts. This was disputed by "Billboard", which said that the two billion views had been moved to Vevo, since the videos were no longer active on YouTube. On August 5, 2015, YouTube removed the feature which caused a video's view count to freeze at "301" (later "301+") until the actual count was verified to prevent view count fraud. YouTube view counts once again updated in real time.

, China and North Korea permanently block accessing YouTube, while Iran blocks YouTube on only one internet service provider. YouTube was blocked in Uzbekistan in October 2018 for unknown reasons. Access to Facebook had been blocked a month earlier. People in the country rely on virtual private network software to circumvent the blockage. On January 15, it was reported that the blockage had been repealed, but it lasted only for 6-7 hours.

Governments block YouTube for a variety of reasons, including:

In some countries, YouTube is completely blocked, either through a long term standing ban or for more limited periods of time such as during periods of unrest, the run-up to an election, or in response to upcoming political anniversaries. In other countries access to the website as a whole remains open, but access to specific videos is blocked. In cases where the entire site is banned due to one particular video, YouTube will often agree to remove or limit access to that video in order to restore service. Businesses, schools, government agencies, and other private institutions often block social media sites, including YouTube, due to bandwidth limitations and the site's potential for distraction.

Several countries have previously blocked access to YouTube:General

The HTML5 specification introduced the video element for the purpose of playing videos, partially replacing the object element. HTML5 video is intended by its creators to become the new standard way to show video on the web, instead of the previous de facto standard of using the proprietary Adobe Flash plugin, though early adoption was hampered by lack of agreement as to which video coding formats and audio coding formats should be supported in web browsers.

HTML5 video

The  element started being discussed by the WHATWG in October 2006.. The  element was proposed by Opera Software in February 2007. Opera also released a preview build that was showcased the same day, and a manifesto that called for video to become a first-class citizen of the web.

The following HTML5 code fragment will embed a WebM video into a web page.

The "controls" attribute enables the browser's own user interface for controlling playback. Alternatively, playback can be controlled with JavaScript, which the web designer can use to create a custom user interface. The optional "poster" attribute specifies an image to show in the video's place before playback is started. Its purpose is to be representative of the video.

Video format support varies among browsers (see below), so a web page can provide video in multiple formats. For other features, browser sniffing is used sometimes, which may be error-prone: any web developer's knowledge of browsers will inevitably be incomplete or not up-to-date. The browser in question "knows best" what formats it can use. The "video" element supports fallback through specification of multiple sources. Using any number of  elements, as shown below, the browser will choose automatically which file to download. Alternatively, the JavaScript canPlayType() function can be used to achieve the same. The "type" attribute specifies the MIME type and possibly a list of codecs, which helps the browser to determine whether it can decode the file. Even with only one choice, such hints may be necessary to a browser for querying its multimedia framework for third party codecs.

The HTML5 specification does not specify which video and audio formats browsers should support. User agents are free to support any video formats they feel are appropriate, but content authors cannot assume that any video will be accessible by all complying user agents, since user agents have no minimal set of video and audio formats to support.

The HTML5 Working Group considered it desirable to specify at least one video format which all user agents (browsers) should support. The ideal format in this regard would:

Initially, Ogg Theora was the recommended standard video format in HTML5, because it was not affected by any known patents. But on 10 December 2007, the HTML5 specification was updated, replacing the reference to concrete formats:
with a placeholder:
The result has been the polarisation of HTML5 video between industry-standard, ISO-defined but patented formats, and free, open formats.

Although Theora is not affected by known non-free patents, Apple has expressed concern about unknown patents that might affect it, whose owners might be waiting for a corporation with extensive financial resources to use the format before suing. Formats like H.264 might also be subject to unknown patents in principle, but they have been deployed much more widely and so it is presumed that any patent-holders would have already made themselves known. Apple has also opposed requiring Ogg format support in the HTML standard (even as a "should" requirement) on the grounds that some devices might support other formats much more easily, and that HTML has historically not required particular formats for anything.

Some web developers criticized the removal of the Ogg formats from the specification. A follow-up discussion also occurred on the W3C questions and answers blog.

Mozilla and Opera support only the open formats of Theora and WebM. Google stated its intention to remove support for H.264 in 2011, specifically for the HTML5 video tag. Although it has been removed from Chromium, it has yet to be removed from Google Chrome five years later.

The adaptive bitrate streaming standard MPEG-DASH can be used in Web browsers via the HTML5 Media Source Extensions (MSE) and JavaScript-based DASH players. Such players are, e.g., the open-source project dash.js of the DASH Industry Forum, but there are also products such as bitdash of bitmovin (using HTML5 with JavaScript, but also a Flash-based DASH players for legacy Web browsers not supporting the HTML5 MSE).

Google's acquisition of On2 in 2010 resulted in its acquisition of the VP8 video format. Google has provided a royalty-free license to use VP8. Google also started WebM, which combines the standardized open source VP8 video codec with Vorbis audio in a Matroska based container. The opening of VP8 was welcomed by the Free Software Foundation.

When Google announced in January 2011 that it would end native support of H.264 in Chrome, criticism came from many quarters including Peter Bright of Ars Technica and Microsoft web evangelist Tim Sneath, who compared Google's move to declaring Esperanto the official language of the United States. However, Haavard Moen of Opera Software strongly criticized the Ars Technica article and Google responded to the reaction by clarifying its intent to promote WebM in its products on the basis of openness.

After the launch of WebM, Mozilla and Opera have called for the inclusion of VP8 in HTML.

On 7 March 2013, Google Inc. and MPEG LA, LLC announced agreements covering techniques that "may be essential" to VP8, with Google receiving a license from MPEG LA and 11 patent holders, and MPEG LA ending its efforts to form a VP8 patent pool.

In 2012, VP9 was released by Google as a successor to VP8, also open and royalty free.

At the end of 2017 the new AV1 format developed by the Alliance for Open Media (AOMedia) as the evolution of VP9 has reached the feature freeze, and the bitstream freeze is expected for January 2018. Firefox nightly builds already include support for AV1.

H.264/MPEG-4 AVC is widely used, and has good speed, compression, hardware decoders, and video quality, but is patent-encumbered. Users of H.264 need licenses either from the individual patent holders, or from the MPEG LA, a group of patent holders including Microsoft and Apple, except for some Internet broadcast video uses. H.264 is usually used in the MP4 container format, together with Advanced Audio Coding (AAC) audio. AAC is also patented in itself, so users of MP4 will have to license both H.264 and AAC.

In June 2009, the WHATWG concluded that no existing format was suitable as a specified requirement.

Apple still only supports H.264, but Microsoft now supports VP9 and WebM, and has pledged support for AV1.

On 30 October 2013, Cisco announced that it was making a binary H.264 module available for download. Cisco will pay the costs of patent licensing for those binary modules "when downloaded by the using software while it is being installed", making H.264 free to use in that specific case.

In the announcement, Cisco cited its desire of furthering the use of the WebRTC project as the reason, since WebRTC's video chat feature will benefit from having a video format supported in all browsers. The H.264 module will be available on "all popular or feasibly supportable platforms, which can be loaded into any application".

Cisco is also planning to publish source code for those modules under BSD license, but without paying the royalties, so the code will practically be free software only in countries without H.264 software patents, which has already been true about other existing implementations.

Also on 30 October 2013, Mozilla's Brendan Eich announced that Firefox would automatically download Cisco's H.264 module when needed by default. He also noted that the binary module is not a perfect solution, since users do not have full free software rights to "modify, recompile, and redistribute without license agreements or fees". Thus Xiph and Mozilla continue the development of Daala.

OpenH264 only supports the "baseline" profile of H.264, and does not by itself address the need for an AAC decoder. Therefore, it is not considered sufficient for typical MP4 web video, which is typically in the "high" profile with AAC audio.
However, for use in WebRTC, the omission of AAC was justified in the release announcement: "the standards bodies have aligned on Opus and G.711 as the common audio codecs for WebRTC". There is doubt as to whether a capped global licensing of AAC, like Cisco's for H.264, is feasible after AAC's licensing bureau removed the price cap shortly after the release of OpenH264.

This table shows which video formats are "likely" to be supported by a given user agent. Most of the browsers listed here use a multimedia framework for decoding and display of video, instead of incorporating such software components. It is not generally possible to tell the set of formats supported by a multimedia framework without querying it, because that depends on the operating system and third party codecs. In these cases, video format support is an attribute of the framework, not the browser (or its layout engine), assuming the browser properly queries its multimedia framework before rejecting unknown video formats. In some cases, the support listed here is not a function of either codecs available within the operating system's underlying media framework, or of codec capabilities built into the browser, but rather could be by a browser add-on that might, for example, bypass the browser's normal HTML parsing of the  tag to embed a plug-in based video player.

Note that a video file normally contains both video and audio content, each encoded in its own format. The browser has to support both the video and audio formats. See HTML5 audio for a table of which audio formats are supported by each browser.

The video format can be specified by MIME type in HTML (see example). MIME types are used for querying multimedia frameworks for supported formats.

Of these browsers, only Firefox and Opera employ libraries for built-in decoding. In practice, Internet Explorer and Safari can also guarantee certain format support, because their manufacturers also make their multimedia frameworks. At the other end of the scale, Konqueror has identical format support to Internet Explorer when run on Windows, and Safari when run on Mac, but the selected support here for Konqueror is the typical for GNU/Linux, where Konqueror has most of its users. In general, the format support of browsers is much dictated by conflicting interests of vendors, specifically that Media Foundation and QuickTime support commercial standards, whereas GStreamer and Phonon cannot legally support other than free formats by default on the free operating systems that they are intended for.

HTML has support for digital rights management (DRM, restricting how content can be used) via the HTML5 Encrypted Media Extensions (EME). The addition of DRM is controversial because it allows restricting users' freedom to use media restricted by DRM, even where fair use gives users the legal right to do so. A main argument in W3C's approval of EME was that the video content would otherwise be delivered in plugins and apps, and not in the web browser.

In 2013 Netflix added support for HTML5 video using EME, beside their old delivery method using a Silverlight plugin (also with DRM).

In 2010, in the wake of Apple iPad launch and after Steve Jobs announced that Apple mobile devices would not support Flash, a number of high-profile sites began to serve H.264 HTML5 video instead of Adobe Flash for user-agents identifying as iPad. HTML5 video was not as widespread as Flash videos, though there were rollouts of experimental HTML5-based video players from DailyMotion (using Ogg Theora and Vorbis format), YouTube (using the H.264 and WebM formats), and Vimeo (using the H.264 format).

Support for HTML5 video has been steadily increasing. In June 2013, Netflix added support for HTML5 video. In January 2015, YouTube switched to using HTML5 video instead of Flash by default. In December 2015, Facebook switched from Flash to HTML5 for all video content.

As of 2016, Flash is still widely installed on desktops, while generally not being supported on mobile devices such as smartphones. The Flash plugin is widely assumed, including by Adobe, to be destined to be phased out, which will leave HTML5 video as the only widely supported method to play video on the World Wide Web. Chrome, Firefox, Safari, and Edge, have plans to make almost all flash content click to play in 2017. The only major browser which does not have announced plans to deprecate Flash is Internet Explorer. Adobe announced on 25 July 2017 that they would be permanently ending development of Flash in 2020.

In 2007, YouTube offered videos in HTML5 format to support the iPhone and iPad, which did not support Flash Player. After a controversy with Apple, Adobe stopped developing Flash Player for Mobile, focussing its efforts on Adobe AIR applications and HTML5 animation. In 2015, Google introduced Google Swiffy to convert Flash animation to HTML5, a tool Google would use to automatically convert Flash web ads for mobile devices. In 2016, Google discontinued Swiffy and its support. In 2015, YouTube switched to HTML5 technology on all devices, however it will preserve the Flash-based video player for older web browsers.

Adobe Flash

Adobe Flash is a deprecated multimedia software platform used for production of animations, rich Internet applications, desktop applications, mobile applications, mobile games and embedded web browser video players. Flash displays text, vector graphics and raster graphics to provide animations, video games and applications. It allows streaming of audio and video, and can capture mouse, keyboard, microphone and camera input. Related development platform Adobe AIR continues to be supported.

Artists may produce Flash graphics and animations using Adobe Animate. Software developers may produce applications and video games using Adobe Flash Builder, FlashDevelop, Flash Catalyst, or any text editor when used with the Apache Flex SDK.

End-users can view Flash content via Flash Player (for web browsers), AIR (for desktop or mobile apps) or third-party players such as Scaleform (for video games). Adobe Flash Player (supported on Microsoft Windows, macOS and Linux) enables end-users to view Flash content using web browsers. Adobe Flash Lite enabled viewing Flash content on older smartphones, but has been discontinued and superseded by Adobe AIR.

The ActionScript programming language allows the development of interactive animations, video games, web applications, desktop applications and mobile applications. Programmers can implement Flash software using an IDE such as Adobe Animate, Adobe Flash Builder, Adobe Director, FlashDevelop and Powerflasher FDT. Adobe AIR enables full-featured desktop and mobile applications to be developed with Flash and published for Windows, macOS, Android, iOS, Xbox One, PlayStation 4, Nintendo Wii U, and Switch.

Although Flash was previously a dominant platform for online multimedia content, it is slowly being abandoned as Adobe favors a transition to HTML5. Flash Player has been deprecated and has an official end-of-life at the end of 2020. However, Adobe will continue to develop Adobe AIR, a related technology for building stand-alone applications and games.

In the early 2000s, Flash was widely installed on desktop computers, and was commonly used to display interactive web pages, online games, and to playback video and audio content. In 2005, YouTube was founded by former PayPal employees, and it used Flash Player as a means to display compressed video content on the web.

Between 2000 and 2010, numerous businesses used Flash-based websites to launch new products, or to create interactive company portals. Notable users include Nike, Hewlett-Packard, Nokia, General Electric, World Wildlife Fund, HBO, Cartoon Network, Disney and Motorola. After Adobe introduced hardware-accelerated 3D for Flash (Stage3D), Flash websites saw a growth of 3D content for product demonstrations and virtual tours.

After Flash 5 introduced ActionScript in 2000, developers combined the visual and programming capabilities of Flash to produce interactive experiences and applications for the Web. Such Web-based applications eventually came to be known as "Rich Internet Applications" (RIAs).

In 2004, Macromedia Flex was released, and specifically targeted the application development market. Flex introduced new user interface components, advanced data visualization components, data remoting, and a modern IDE (Flash Builder). Flex competed with Asynchronous JavaScript and XML (AJAX) and Microsoft Silverlight during its tenure. Flex was upgraded to support integration with remote data sources, using AMF, BlazeDS, Adobe LiveCycle, Amazon Elastic Compute Cloud, and others. As of 2015, Flex applications can be published for desktop platforms using Adobe AIR.

Between 2006 and 2016, the Speedtest.net web service conducted over 9.0 billion speed tests using an RIA built with Adobe Flash. In 2016, the service shifted to HTML5 due to the decreasing availability of Adobe Flash Player on PCs.

As of 2016, Web applications and RIAs can be developed with Flash using the ActionScript 3.0 programming language and related tools such as Adobe Flash Builder. Third-party IDEs such as FlashDevelop and Powerflasher FDT also enable developers to create Flash games and applications, and are generally similar to Microsoft Visual Studio. Flex applications are typically built using Flex frameworks such as PureMVC.

Flash video games were popular on the Internet, with portals like Newgrounds dedicated to hosting of Flash-based games. Popular games developed with Flash include "Angry Birds", "Clash of Clans", "FarmVille", "AdventureQuest", "Machinarium", "Hundreds", "N", "QWOP" and "Solipskier".

Adobe introduced various technologies to help build video games, including Adobe AIR (to release games for desktop or mobile platforms), Adobe Scout (to improve performance), CrossBridge (to convert C++-based games to run in Flash), and Stage3D (to support GPU-accelerated video games). 3D frameworks like Away3D and Flare3D simplified creation of 3D content for Flash.

Adobe AIR allows creation of Flash-based mobile games, which may be published to the Google Play and Apple app stores.

Flash is also used to build interfaces and HUDs for 3D video games using Scaleform GFx, a technology that renders Flash content within non-Flash video games. Scaleform is supported by more than 10 major video game engines including Unreal Engine, UDK, CryEngine and PhyreEngine, and has been used to provide 3D interfaces for more than 150 major video game titles since its launch in 2003.

Adobe Animate is one of the common animation programs for low-cost 2D television and commercial animation, in competition with Anime Studio and Toon Boom Animation.

Notable users of Flash include DHX Media Vancouver for productions including "Pound Puppies" and "", Fresh TV for Total Drama, Nelvana for "6teen" and "Clone High", Williams Street for "Metalocalypse" and "Squidbillies", Nickelodeon Animation Studios for "Wow! Wow! Wubbzy!", "", among others.

Flash is less commonly used for feature-length animated films; however, 2009's "The Secret of Kells", an Irish film, was animated primarily in Adobe Flash, and was nominated for an Academy Award for Best Animated Feature at the 82nd Academy Awards.

Several popular online series are currently produced in Flash, such as the Emmy Award-winning "Off-Mikes", produced by ESPN and Animax Entertainment; "Happy Tree Friends"; "Gotham Girls", produced by Warner Brothers; "Crime Time", produced by Future Thought Productions and "Homestar Runner" produced by Mike and Matt Chapman.

Various third-party software packages designed for traditionally trained cartoonists and animators can publish animations in the SWF format.

The precursor to Flash was a product named SmartSketch, published by FutureWave Software. The company was founded by Charlie Jackson, Jonathan Gay, and Michelle Welsh. SmartSketch was a vector drawing application for pen computers running the PenPoint OS. When PenPoint failed in the marketplace, SmartSketch was ported to Microsoft Windows and Mac OS.

As the Internet became more popular, FutureWave realized the potential for a vector-based web animation tool that might challenge Macromedia Shockwave technology. In 1995, FutureWave modified SmartSketch by adding frame-by-frame animation features and released this new product as FutureSplash Animator on Macintosh and PC.

FutureWave approached Adobe Systems with an offer to sell them FutureSplash in 1995, but Adobe turned down the offer at that time. Microsoft wanted to create an "online TV network" (MSN 2.0) and adopted FutureSplash animated content as a central part of it. Disney Online used FutureSplash animations for their subscription-based service Disney's Daily Blast. Fox Broadcasting Company launched The Simpsons using FutureSplash.

In November 1996, FutureSplash was acquired by Macromedia, and Macromedia re-branded and released "FutureSplash Animator" as "Macromedia Flash 1.0". Flash was a two-part system, a graphics and animation editor known as Macromedia Flash, and a player known as Macromedia Flash Player.

"FutureSplash Animator" was an animation tool originally developed for pen-based computing devices. Due to the small size of the "FutureSplash Viewer", it was particularly suited for download on the Web. Macromedia distributed Flash Player as a free browser plugin in order to quickly gain market share. By 2005, more computers worldwide had Flash Player installed than any other Web media format, including Java, QuickTime, RealNetworks and Windows Media Player.

Macromedia upgraded the Flash system between 1996 and 1999 adding MovieClips, Actions (the precursor to ActionScript), Alpha transparency, and other features. As Flash matured, Macromedia's focus shifted from marketing it as a graphics and media tool to promoting it as a Web application platform, adding scripting and data access capabilities to the player while attempting to retain its small footprint.

In 2000, the first major version of ActionScript was developed, and released with "Flash 5". Actionscript 2.0 was released with "Flash MX 2004" and supported object-oriented programming, improved UI components and other programming features. The last version of Flash released by Macromedia was "Flash 8", which focused on graphical upgrades such as filters (blur, drop shadow, etc.), blend modes (similar to Adobe Photoshop), and advanced features for FLV video.

Macromedia was acquired by Adobe Systems in 2005, and the entire Macromedia product line including Flash, Dreamweaver, Director/Shockwave, Fireworks (which has since been discontinued) and Authorware is now handled by Adobe.

In 2007, Adobe's first version release was "Adobe Flash CS3 Professional", the ninth major version of Flash. It introduced the ActionScript 3.0 programming language, which supported modern programming practices and enabled business applications to be developed with Flash. Adobe Flex Builder (built on Eclipse) targeted the enterprise application development market, and was also released the same year. Flex Builder included the Flex SDK, a set of components that included charting, advanced UI, and data services ("Flex Data Services").

In 2008, Adobe released the tenth version of Flash, "Adobe Flash CS4". Flash 10 improved animation capabilities within the Flash editor, adding a motion editor panel (similar to Adobe After Effects), inverse kinematics (bones), basic 3D object animation, object-based animation, and other text and graphics features. "Flash Player 10" included an in-built 3D engine (without GPU acceleration) that allowed basic object transformations in 3D space (position, rotation, scaling).

Also in 2008, Adobe released the first version of Adobe Integrated Runtime (later re-branded as "Adobe AIR"), a runtime engine that replaced Flash Player, and provided additional capabilities to the ActionScript 3.0 language to build desktop and mobile applications. With AIR, developers could access the file system (the user's files and folders), and connected devices such as joystick, gamepad and sensors for the first time.

In 2011, "Adobe Flash Player 11" was released, and with it the first version of Stage3D, allowing GPU-accelerated 3D rendering for Flash applications and games on desktop platforms such as Microsoft Windows and Mac OS X. Adobe further improved 3D capabilities from 2011 to 2013, adding support for 3D rendering on Android and iOS platforms, alpha-channels, compressed textures, texture atlases, and other features. Adobe AIR was upgraded to support 64-bit computers, and to allow developers to add additional functionality to the AIR runtime using "AIR Native Extensions" (ANE).

In 2014, Adobe AIR reached a milestone with over 100,000 unique applications built, and over 1 billion installations logged across the world (May 2014). Adobe AIR was voted the "Best Mobile Application Development" product at the Consumer Electronics Show on two consecutive years (CES 2014 and CES 2015). In 2016, Adobe renamed Flash Professional, the primary authoring software for Flash content, to Adobe Animate to reflect its growing use for authoring HTML5 content in favour of Flash content.

On May 1, 2008, Adobe announced the "Open Screen Project", with the intent of providing a consistent application interface across devices such as personal computers, mobile devices, and consumer electronics. When the project was announced, seven goals were outlined: the abolition of licensing fees for Adobe Flash Player and Adobe Integrated Runtime, the removal of restrictions on the use of the Shockwave Flash (SWF) and Flash Video (FLV) file formats, the publishing of application programming interfaces for porting Flash to new devices, and the publishing of The Flash Cast protocol and Action Message Format (AMF), which let Flash applications receive information from remote databases.

, the specifications removing the restrictions on the use of SWF and FLV/F4V specs have been published. The Flash Cast protocol—now known as the Mobile Content Delivery Protocol—and AMF protocols have also been made available, with AMF available as an open source implementation, BlazeDS.

The list of mobile device providers who have joined the project includes Palm, Motorola, and Nokia, who, together with Adobe, have announced a $10 million Open Screen Project fund., the Open Screen Project is no longer accepting new applications according to partner BSQuare. However paid licensing is still an option for device makers who want to use Adobe software.

Although Flash was previously a dominant platform for online multimedia content, it is slowly being abandoned as Adobe favors a transition to HTML5 due to inherent security flaws and significant resources required to maintain the platform. Apple restricted the use of Flash on iOS in 2010 due to concerns that it performed poorly on its mobile devices, had negative impact on battery life, and was deemed unnecessary for online content. As a result, it was not adopted by Apple for its smartphone and tablet devices, which also reduced its user base and encouraged wider adoption of HTML5 features such as the canvas and video elements, which can replace Flash without the need for plugins. In 2015, Adobe rebranded its Flash authoring environment as Adobe Animate to emphasize its expanded support for HTML5 authoring, and stated that it would "encourage content creators to build with new web standards" rather than using Flash. In July 2017, Adobe announced that it would declare Flash to be end-of-life at the end of 2020, and will cease support, distribution, and security updates to Flash Player. After the announcement, developers have started a petition to turn Flash into an open-source project, leading to controversy.

The Flash Platform will continue in the form of Adobe AIR, which Adobe will continue to develop, and OpenFL, a multi-target open-source implementation of the Flash API.

Flash source files are in the FLA format, and contain graphics and animation, as well as embedded assets such as bitmap images, audio files and FLV video files. The Flash source file format is a proprietary format and Adobe Animate is the only available authoring tool capable of editing such files. Flash source files (.fla) may be compiled into Flash movie files (.swf) using Adobe Animate. Note that FLA files can be edited, but output (.swf) files cannot.

Flash movie files are in the "SWF" format, traditionally called "ShockWave Flash" movies, "Flash movies", or "Flash applications", usually have a.swf file extension, and may be used in the form of a web page plug-in, strictly "played" in a standalone Flash Player, or incorporated into a self-executing Projector movie (with the.exe extension in Microsoft Windows). Flash Video files have a.flv file extension and are either used from within.swf files or played through a flv-aware player, such as VLC, or QuickTime and Windows Media Player with external codecs added.

The use of vector graphics combined with program code allows Flash files to be smaller—and thus allows streams to use less bandwidth—than the corresponding bitmaps or video clips. For content in a single format (such as just text, video, or audio), other alternatives may provide better performance and consume less CPU power than the corresponding Flash movie, for example when using transparency or making large screen updates such as photographic or text fades.

In addition to a vector-rendering engine, the Flash Player includes a virtual machine called the ActionScript Virtual Machine (AVM) for scripting interactivity at run-time, with video, MP3-based audio, and bitmap graphics. As of Flash Player 8, it offers two video codecs: On2 Technologies VP6 and Sorenson Spark, and run-time JPEG, Progressive JPEG, PNG, and GIF capability.

Flash Player 11 introduced a full 3D shader API, called Stage3D, which is fairly similar to WebGL. Stage3D enables GPU-accelerated rendering of 3D graphics within Flash games and applications, and has been used to build Angry Birds, and a couple of other notable games.

Various 3D frameworks have been built for Flash using Stage3D, such as Away3D 4, CopperCube, Flare3D, Starling. Professional game engines like Unreal Engine and Unity also export Flash versions which use Stage3D to render 3D graphics.

Virtually all browser plugins for video are free of charge and cross-platform, including Adobe's offering of Flash Video, which was introduced with Flash version 6. Flash Video has been a popular choice for websites due to the large installed user base and programmability of Flash. In 2010, Apple publicly criticized Adobe Flash, including its implementation of video playback for not taking advantage of hardware acceleration, one reason Flash is not to be found on Apple's mobile devices. Soon after Apple's criticism, Adobe demoed and released a beta version of Flash 10.1, which uses available GPU hardware acceleration even on a Mac. Flash 10.2 beta, released December 2010, adds hardware acceleration for the whole video rendering pipeline.

Flash Player supports two distinct modes of video playback, and hardware accelerated video decoding may not be used for older video content. Such content causes excessive CPU usage compared to comparable content played with other players.

In tests done by Ars Technica in 2008 and 2009, Adobe Flash Player performed better on Windows than Mac OS X and Linux with the same hardware.
Performance has later improved for the latter two, on Mac OS X with Flash Player 10.1, and on Linux with Flash Player 11.

Flash Audio is most commonly encoded in MP3 or AAC (Advanced Audio Coding) however it can also use ADPCM, Nellymoser (Nellymoser Asao Codec) and Speex audio codecs. Flash allows sample rates of 11, 22 and 44.1 kHz. It cannot have 48 kHz audio sample rate, which is the standard TV and DVD sample rate.

On August 20, 2007, Adobe announced on its blog that with Update 3 of Flash Player 9, Flash Video will also implement some parts of the MPEG-4 international standards. Specifically, Flash Player will work with video compressed in H.264 (MPEG-4 Part 10), audio compressed using AAC (MPEG-4 Part 3), the F4V, MP4 (MPEG-4 Part 14), M4V, M4A, 3GP and MOV multimedia container formats, 3GPP Timed Text specification (MPEG-4 Part 17), which is a standardized subtitle format and partial parsing capability for the 'ilst' atom, which is the ID3 equivalent iTunes uses to store metadata. MPEG-4 Part 2 and H.263 will not work in F4V file format. Adobe also announced that it will be gradually moving away from the FLV format to the standard ISO base media file format (MPEG-4 Part 12) owing to functional limits with the FLV structure when streaming H.264. The final release of the Flash Player implementing some parts of MPEG-4 standards had become available in Fall 2007.

Adobe Flash Player 10.1 does not have acoustic echo cancellation, unlike the VoIP offerings of Skype and Google Voice, making this and earlier versions of Flash less suitable for group calling or meetings. Flash Player 10.3 Beta incorporates acoustic echo cancellation.

"ActionScript" is the programming language used by Flash. It is an enhanced superset of the ECMAScript programming language, with a classical Java-style class model, rather than JavaScript's prototype model.

In October 1998, Macromedia disclosed the Flash Version 3 Specification on its website. It did this in response to many new and often semi-open formats competing with SWF, such as Xara's Flare and Sharp's Extended Vector Animation formats. Several developers quickly created a C library for producing SWF. In February 1999, MorphInk 99 was introduced, the first third-party program to create SWF files. Macromedia also hired Middlesoft to create a freely available developers' kit for the SWF file format versions 3 to 5.

Macromedia made the Flash Files specifications for versions 6 and later available only under a non-disclosure agreement, but they are widely available from various sites.

In April 2006, the Flash SWF file format specification was released with details on the then newest version format (Flash 8). Although still lacking specific information on the incorporated video compression formats (On2, Sorenson Spark, etc.), this new documentation covered all the new features offered in Flash v8 including new ActionScript commands, expressive filter controls, and so on. The file format specification document is offered only to developers who agree to a license agreement that permits them to use the specifications only to develop programs that can export to the Flash file format. The license does not allow the use of the specifications to create programs that can be used for playback of Flash files. The Flash 9 specification was made available under similar restrictions.

In June 2009, Adobe launched the Open Screen Project (Adobe link), which made the SWF specification available without restrictions. Previously, developers could not use the specification for making SWF-compatible players, but only for making SWF-exporting authoring software. The specification still omits information on codecs such as Sorenson Spark, however.

The Adobe Animate authoring program is primarily used to design graphics and animation and publish the same for websites, web applications, and video games. The program also offers limited support for audio and video embedding, and ActionScript scripting.

Adobe released Adobe LiveMotion, designed to create interactive animation content and export it to a variety of formats, including SWF. LiveMotion failed to gain any notable user base.

In February 2003, Macromedia purchased Presedia, which had developed a Flash authoring tool that automatically converted PowerPoint files into Flash. Macromedia subsequently released the new product as Breeze, which included many new enhancements.

Various free and commercial software packages can output animations into the Flash SWF format, suitable for display on the web, including:

The Flash 4 Linux project was an initiative to develop an open source Linux application as an alternative to Adobe Animate. Development plans included authoring capacity for 2D animation, and tweening, as well as outputing SWF file formats. F4L evolved into an editor that was capable of authoring 2D animation and publishing of SWF files. Flash 4 Linux was renamed UIRA. UIRA intended to combine the resources and knowledge of the F4L project and the Qflash project, both of which were Open Source applications that aimed to provide an alternative to the proprietary Adobe Flash.

Adobe provides a series of tools to develop software applications and video games for Flash:

Third-party development tools have been created to assist developers in creating software applications and video games with Flash.

Adobe Flash Player is the multimedia and application player originally developed by Macromedia and acquired by Adobe Systems. It plays SWF files, which can be created by Adobe Animate, Apache Flex, or a number of other Adobe Systems and 3rd party tools. It has support for a scripting language called ActionScript, which can be used to display Flash Video from an SWF file.

Scaleform GFx is a commercial alternative Flash player that features fully hardware-accelerated 2D graphics rendering using the GPU. Scaleform has high conformance with both Flash 10 ActionScript 3 and Flash 8 ActionScript 2. Scaleform GFx is a game development middleware solution that helps create graphical user interfaces or HUDs within 3D video games. It does not work with web browsers.

IrfanView, an image viewer, uses Flash Player to display SWF files.

OpenFL is an open-source implementation of the Adobe Flash API. It allows developers to build a single application against the OpenFL APIs and simultaneously target multiple platforms including iOS, Android, HTML5 (choice of Canvas, WebGL, SVG or DOM), Windows, macOS, Linux, WebAssembly, Flash, AIR, PlayStation 4, PlayStation 3, PlayStation Vita, Xbox One, Wii U, TiVo, Raspberry Pi, and Node.js.

OpenFL mirrors the Flash API for graphical operations. OpenFL applications can be written in Haxe, JavaScript (EcmaScript 5 or 6+), or TypeScript.

Lightspark is a free and open source SWF player that supports most of ActionScript 3.0 and has a Mozilla-compatible plug-in. It will fall back on Gnash, a free SWF player supporting ActionScript 1.0 and 2.0 (AVM1) code. Lightspark supports OpenGL-based rendering for 3D content. The player is also compatible with H.264 Flash videos on YouTube.

Gnash aims to create a software player and browser plugin replacement for the Adobe Flash Player. Gnash can play SWF files up to version 7, and 80% of ActionScript 2.0. Gnash run on Windows, Linux and other platforms for the 32-bit, 64-bit, and other operating systems, but development has slowed significantly in recent years.

Shumway was an open source Flash Player released by Mozilla in November 2012. It was built in JavaScript and is thus compatible with modern web-browsers. In early October 2013, Shumway was included by default in the Firefox nightly branch. Shumway rendered Flash contents by translating contents inside Flash files to HTML5 elements, and running an ActionScript interpreter in JavaScript. It supported both AVM1 and AVM2, and ActionScript versions 1, 2, and 3. Development of Shumway ceased in early 2016.

Adobe Flash has been deprecated. The latest version of Adobe Flash Player is available for three major desktop platforms, including Windows, macOS and Linux. On Linux the PPAPI plug-in is available; the NPAPI version wasn't updated to new major versions for a while until Adobe changed its mind on stopping support and its former plan to discontinue "in 2017".

Adobe Flash Player is available in four flavors:The "ActiveX" version is an ActiveX control for use in Internet Explorer and any other Windows applications that supports ActiveX technology. The "Plug-in" versions are available for browsers supporting either NPAPI or PPAPI plug-ins on Microsoft Windows, macOS and Linux. The "projector" version is a standalone player that can open SWF files directly.

The following table documents Flash Player and Adobe AIR support on desktop operating systems:

The latest version of Adobe AIR, version 18, contains Adobe Flash Player 18, and is available for Windows XP and later, as well as macOS. Official support for desktop Linux distributions ceased in June 2011 with version 2.6.

Adobe Flash Player was available for a variety of mobile operating systems, including Android (between versions 2.2 and 4.0.4), Pocket PC/Windows CE, QNX (e.g. on BlackBerry PlayBook), Symbian, Palm OS, and webOS (since version 2.0). Flash Player for smart phones was made available to handset manufacturers at the end of 2009.

However, in November 2011, Adobe announced the withdrawal of support for Flash Player on mobile devices. Adobe continues to support deploying Flash-based content as mobile applications via Adobe AIR.

Adobe is reaffirming its commitment to "aggressively contribute" to HTML5. Adobe announced the end of Flash for mobile platforms or TV, instead focusing on HTML5 for browser content and Adobe AIR for the various mobile application stores and described it as "the beginning of the end". BlackBerry LTD (formerly known as RIM) announced that it would continue to develop Flash Player for the PlayBook.

There is no Adobe Flash Player for iOS devices (iPhone, iPad and iPod Touch). However, Flash content can be made to run on iOS devices in a variety of ways:

The mobile version of Internet Explorer for Windows Phone cannot play Flash content, however Flash support is still present on the tablet version of Windows.

Adobe AIR was released in 2008, and allows the creation of mobile applications and mobile games using Flash and ActionScript. Notable mobile games built with Flash include "Angry Birds", "Machinarium" and "Defend Your Castle".

Using AIR, developers can access the full Adobe Flash functionality, including text, vector graphics, raster graphics, video, audio, camera and microphone capability. Adobe AIR also includes additional features such as file system integration, native client extensions, desktop integration and access to connected devices and sensors.

AIR applications can be published as native phone applications on certain mobile operating systems, such as Android (ARM Cortex-A8 and above) and Apple iOS.

The following table explains to what extent Adobe AIR can run on various mobile operating systems:

Adobe Flash Lite is a lightweight version of Adobe Flash Player intended for mobile phones and other portable electronic devices like Chumby and iRiver.

On the emerging single-board enthusiast market, as substantially popularized by the Raspberry Pi, support from Adobe is lacking. However, the open-source player Gnash has been ported and found to be useful.

OpenFL is an open-source implementation of the Adobe Flash technology. It allows developers to build a single application against the OpenFL APIs, and simultaneously target multiple platforms including Flash/AIR, HTML5, Windows, Android, Tizen, Neko, BlackBerry and webOS. OpenFL mirrors the Flash API for graphical operations. OpenFL applications are written in Haxe, a modern multi-platform programming language.

More than 500 video games have been developed with OpenFL, including the BAFTA-award-winning game "Papers, Please", Rymdkapsel, Lightbot and Madden NFL Mobile.

HTML5 is often cited as an alternative to Adobe Flash technology usage on web pages. Adobe released a tool that converts Flash to HTML5, and in June 2011, Google released an experimental tool that does the same. In January 2015, YouTube defaulted to HTML5 players to better support more devices.

The following tools allow running Flash content in web browsers using HTML5:Websites built with Adobe Flash will not function on most modern mobile devices running Google Android or iOS (iPhone, iPad). The only alternative is using HTML5 and responsive web design to build websites that support both desktop and mobile devices.

However, Flash is still used to build mobile games using Adobe AIR. Such games will not work in mobile web browsers, but must be installed via the appropriate app store.

The reliance on Adobe for decoding Flash makes its use on the World Wide Web a concern—the completeness of its public specifications are debated, and no complete implementation of Flash is publicly available in source code form with a license that permits reuse. Generally, public specifications are what makes a format re-implementable (see future proofing data storage), and reusable codebases can be ported to new platforms without the endorsement of the format creator.

Adobe's restrictions on the use of the SWF/FLV specifications were lifted in February 2009 (see Adobe's Open Screen Project). However, despite efforts of projects like Gnash, Swfdec and Lightspark, a complete free Flash player is yet to be seen, as of September 2011. For example, Gnash cannot use SWF v10 yet. Notably, Gnash was listed on the Free Software Foundation's high priority list, from at least 2007, to its overdue removal in January 2017.

Notable advocates of free software, open standards, and the World Wide Web have warned against the use of Flash:

The founder of Mozilla Europe, Tristan Nitot, stated in 2008:
Companies building websites should beware of proprietary rich-media technologies like Adobe's Flash and Microsoft's Silverlight. (...) You're producing content for your users and there's someone in the middle deciding whether users should see your content.

Representing open standards, inventor of CSS and co-author of HTML5, Håkon Wium Lie explained in a Google tech talk of 2007, entitled "the  element", the proposal of Theora as the format for HTML5 video:
I believe very strongly, that we need to agree on some kind of baseline video format if [the video element] is going to succeed. Flash is today the baseline format on the web. The problem with Flash is that it's not an open standard.

Representing the free software movement, Richard Stallman stated in a speech in 2004 that: "The use of Flash in websites is a major problem for our community."

Usability consultant Jakob Nielsen published an Alertbox in 2000 entitled, "Flash: 99% Bad", stating that "Flash tends to degrade websites for three reasons: it encourages design abuse, it breaks with the Web's fundamental interaction principles, and it distracts attention from the site's core value." Some problems have been at least partially fixed since Nielsen's complaints: Text size can be controlled using full page zoom and it has been possible for authors to include alternative text in Flash since Flash Player 6.

Flash content is usually embedded using the codice_1 or codice_2 HTML element. A web browser that does not fully implement one of these elements displays the replacement text, if supplied by the web page. Often, a plugin is required for the browser to fully implement these elements, though some users cannot or will not install it.

Since Flash can be used to produce content (such as advertisements) that some users find obnoxious or take a large amount of bandwidth to download, some web browsers, by default, do not play Flash content until the user clicks on it, e.g. Konqueror, K-Meleon.

Most current browsers have a feature to block plugins, playing one only when the user clicks it. Opera versions since 10.5 feature native Flash blocking. Opera Turbo requires the user to click to play Flash content, and the browser also allows the user to enable this option permanently. Both Chrome and Firefox have an option to enable "click to play plugins". Equivalent "Flash blocker" extensions are also available for many popular browsers: Firefox has Flashblock and NoScript, Internet Explorer has Foxie, which contains a number of features, one of them named Flashblock. WebKit-based browsers under macOS, such as Apple's Safari, have ClickToFlash.

Firefox (from version 46) rewrites old Flash-only YouTube embed code into YouTube's modern embedded player that is capable of using either HTML5 or Flash. Such embed code is used by non-YouTube sites to embed YouTube's videos, and can still be encountered, for example, on old blogs and forums.

For many years Adobe Flash Player's security record has led many security experts to recommend against installing the player, or to block Flash content. The US-CERT has recommended blocking Flash, and security researcher Charlie Miller recommended "not to install Flash"; however, for people still using Flash, Intego recommended that users get trusted updates "only directly from the vendor that publishes them." As of February 12, 2015, Adobe Flash Player has over 400 CVE entries, of which over 300 lead to arbitrary code execution, and past vulnerabilities have enabled spying via web cameras. Security experts have long predicted the demise of Flash, saying that with the rise of HTML5 "...the need for browser plugins such as Flash is diminishing", as only 7 to 10 percent of websites still use it.

Active moves by third parties to limit the risk began with Steve Jobs in 2010 saying that Apple would not allow Flash on the iPhone, iPod touch and iPad – citing abysmal security as one reason. Flash often used the ability to dynamically change parts of the runtime on languages on OSX to improve their own performance, but caused general instability. In July 2015, a series of newly discovered vulnerabilities resulted in Facebook's chief security officer, Alex Stamos, issuing a call to Adobe to discontinue the software entirely and the Mozilla Firefox web browser, Google Chrome and Apple Safari to blacklist all earlier versions of Flash Player.

As a result, "Adobe has essentially stopped trying to do anything new and innovative with Flash."

Like the HTTP cookie, a flash cookie (also known as a “Local Shared Object”) can be used to save application data. Flash cookies are not shared across domains. An August 2009 study by the Ashkan Soltani and a team of researchers at UC Berkeley found that 50% of websites using Flash were also employing flash cookies, yet privacy policies rarely disclosed them, and user controls for privacy preferences were lacking. Most browsers' cache and history suppress or delete functions did not affect Flash Player's writing Local Shared Objects to its own cache in version 10.2 and earlier, at which point the user community was much less aware of the existence and function of Flash cookies than HTTP cookies. Thus, users with those versions, having deleted HTTP cookies and purged browser history files and caches, may believe that they have purged all tracking data from their computers when in fact Flash browsing history remains. Adobe's own Flash Website Storage Settings panel, a submenu of Adobe's Flash Settings Manager web application, and other editors and toolkits can manage settings for and delete Flash Local Shared Objects.

The HTML5 draft specification adds codice_1 and codice_2 elements for embedding video and audio in HTML documents. The specification had formerly recommended support for playback of Theora video and Vorbis audio encapsulated in Ogg containers to provide for easier distribution of audio and video over the internet by using open standards, but the recommendation was soon after dropped.

Use of Ogg formats in HTML5

Because some visitors and publishers choose not to take part in the use of proprietary software, web content has been made available through open standards in order to reach these users. As multimedia is already mainstream on the web through proprietary data formats (such as Windows Media Video and MP4) and browser plugins (such as Adobe Flash Player), developers had hoped Theora and Vorbis would become part of the HTML5 specification.

Users affiliated with the free software movement claimed the following advantages:

CTO at Opera Software, Håkon Wium Lie explained in a Google tech talk entitled "The  element" the proposal of Theora as the video format for HTML5:
After the presentation, Lie was asked whether Opera will support other formats than Ogg:

Opera Software and Mozilla have been advocates for including the Ogg formats into the HTML standard.
Support has been available in experimental builds of Opera 9.5 since 2007, and Ogg Theora is fully supported since Opera 10.50.
Gecko 1.9.1 (browsers based on this engine include Mozilla Firefox 3.5 and SeaMonkey 2.0), released on June 30, 2009, was the first non-experimental layout engine to support Ogg formats. Google Chrome included support in their 3.0 release (September 2009), along with support for H.264. However, they did not support MPEG-1 (the parts patents on which are thought to have expired), citing concerns over performance.

Microsoft began work in October 2017 on implementing support for Ogg, Vorbis, and Theora in Windows 10 and Microsoft Edge.

On October 17, 2007, the World Wide Web Consortium encouraged interested people to take part in a "Video on the Web Workshop", held on December 12, 2007, for two days. A number of global companies were involved, submitting position papers. Among them, Nokia's paper states that "a W3C-led standardization of a 'free' codec, or the active endorsement of proprietary technology such as Ogg [...] by W3C, is, in our opinion, not helpful". Xiph.org's codecs, while licensed under a BSD-style permissive free software license, implement a standard controlled by Xiph.org themselves, rather than a multi-vendor community such as MPEG. Apple Inc., a member of the MPEG LA, has also opposed the inclusion of Ogg formats in the HTML standard on the grounds that H.264 performs better and is already more widely supported, citing patents on their codec's efficiency and the lack of precedents of "Placing requirements on format support", even at the "SHOULD" level, in HTML specifications.

On December 10, 2007, the HTML 5 specification was updated, replacing the reference to Theora and Vorbis with a placeholder:

The removal of the Ogg formats from the specification made it completely file format neutral, like previous versions of HTML. The decision was criticized by a number of Web developers. A follow-up discussion also occurred on the W3C questions and answers blog.

In response to criticism, the WHATWG has cited concerns over the Ogg formats still being within patent lifetime and thus vulnerable to unknown patents.
Such submarine patents may also exist for formats like MP3. Also, the AVC patent licensing policy is subject to change in a not-yet-clear manner.

, HTML5 video is not currently as widespread as Flash videos, though of recent rollouts of experimental HTML5-based video players on websites, DailyMotion is so far the only one to use Ogg Theora and Vorbis formats, which suggests an increasing early interest in adopting HTML5 video.

"WebRTC Audio Codec and Processing Requirements" Internet standard drafts, published in 2011-2013, require free formats, including Opus, which was developed, among others, by programmers associated with Xiph.Org Foundation (the maintainer of Ogg).