YouTube

=== Video technology ===

YouTube primarily uses the [[VP9]] and [[H.264/MPEG-4 AVC]] video codecs, and the [[Dynamic Adaptive Streaming over HTTP]] protocol.<ref>{{cite book |last1=Barman |first1=Nabajeet |last2=Martini |first2=Maria G. |title=2017 Ninth International Conference on Quality of Multimedia Experience (QoMEX) |chapter=H.264/MPEG-AVC, H.265/MPEG-HEVC and VP9 codec comparison for live gaming video streaming |date=May 2017 |pages=1–6 |doi=10.1109/QoMEX.2017.7965686 |isbn=978-1-5386-4024-1 |s2cid=28395957}}</ref> [[MPEG-4 Part 2]] streams contained within [[3GP and 3G2|3GP]] containers are also provided for low bandwidth connections.<ref name="codec list">{{cite web |year=2018 |title=Youtube video/audio codec list |url=https://gist.github.com/sidneys/7095afe4da4ae58694d128b1034e01e2 |url-status=live |archive-url=https://web.archive.org/web/20210911001956/https://gist.github.com/sidneys/7095afe4da4ae58694d128b1034e01e2 |archive-date=September 11, 2021 |website=[[GitHub]] }} [https://etched.page/?url=https%3A%2F%2Fgist.github.com%2Fsidneys%2F7095afe4da4ae58694d128b1034e01e2 Alt URL] {{Webarchive|url=https://web.archive.org/web/20210911015234/https://etched.page/?url=https://gist.github.com/sidneys/7095afe4da4ae58694d128b1034e01e2 |date=September 11, 2021 }}</ref> By January 2019, YouTube had begun rolling out videos in [[AV1]] format.<ref>{{cite web |url=https://www.youtube.com/playlist?list=PLyqf6gJt7KuHBmeVzZteZUlNUQAVLwrZS |title=AV1 Beta Launch Playlist |via=YouTube |access-date=January 14, 2019 |archive-date=February 16, 2021 |archive-url=https://web.archive.org/web/20210216145744/https://www.youtube.com/playlist?list=PLyqf6gJt7KuHBmeVzZteZUlNUQAVLwrZS |url-status=live }}</ref> In 2021 it was reported that the company was considering requiring AV1 in streaming hardware in order to decrease bandwidth and increase quality.<ref>{{cite web |last=Schoon |first=Ben |date=January 27, 2021 |title=YouTube may require AV1 support in the future |url=https://9to5google.com/2021/01/27/youtube-av1-netflix-requirement/ |access-date=May 5, 2021 |website=[[9to5Google]] |language=en-US |archive-date=April 14, 2023 |archive-url=https://web.archive.org/web/20230414062701/https://9to5google.com/2021/01/27/youtube-av1-netflix-requirement/ |url-status=live }}</ref> Video is usually streamed alongside the [[Opus (audio format)|Opus]] and [[Advanced Audio Coding|AAC]] audio codecs.<ref name="codec list" />

At launch in 2005, viewing YouTube videos on a personal computer required the [[Adobe Flash Player]] plug-in to be installed in the browser.<ref>{{cite news |title=Flash moves on to smart phones |publisher=BBC |url=https://news.bbc.co.uk/1/hi/8287239.stm |access-date=November 30, 2009 |date=October 5, 2009 |first=Jonathan |last=Fildes |archive-date=October 8, 2022 |archive-url=https://web.archive.org/web/20221008233844/http://news.bbc.co.uk/1/hi/8287239.stm |url-status=live }}</ref> 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.<ref name="ditches Flash">{{cite web |last=Protalinski |first=Emil |date=January 27, 2015 |title=YouTube ditches Flash for HTML5 video by default |url=https://venturebeat.com/2015/01/27/youtube-ditches-flash-for-html5-video-by-default/ |access-date=May 5, 2021 |website=VentureBeat |language=en-US |archive-date=May 5, 2021 |archive-url=https://web.archive.org/web/20210505173316/https://venturebeat.com/2015/01/27/youtube-ditches-flash-for-html5-video-by-default/ |url-status=live }}</ref> This allowed videos to be viewed without requiring Adobe Flash Player or any other plug-in to be installed.<ref>{{cite web |url=https://www.downloadsquad.com/2009/11/08/html5-youtube-viewer-close-but-not-quite-there/ |title=HTML5 YouTube viewer: close, but not quite there |archive-url=https://web.archive.org/web/20091110003012/https://www.downloadsquad.com/2009/11/08/html5-youtube-viewer-close-but-not-quite-there/ |archive-date=November 10, 2009 |access-date=December 1, 2017}}</ref> On January 27, 2015, YouTube announced that HTML5 would be the default playback method on [[HTML5 video support|supported browsers]].<ref name="ditches Flash" /> HTML5 video streams use [[Dynamic Adaptive Streaming over HTTP]] (MPEG-DASH), an HTTP-based adaptive bit-rate streaming solution optimizes the bitrate and quality for the available network.<ref>{{cite web |first=Rajeev |last=Tiwari |url=https://streamingcodecs.blogspot.hu/2013/01/mpeg-dash-support-in-youtube.html |title=Streaming Media and RTOS: MPEG-DASH Support in Youtube |publisher=Streamingcodecs.blogspot.hu |date=January 3, 2013 |access-date=March 13, 2014 |archive-date=March 3, 2014 |archive-url=https://web.archive.org/web/20140303041133/http://streamingcodecs.blogspot.hu/2013/01/mpeg-dash-support-in-youtube.html |url-status=live }}</ref>

The platform can serve videos at optionally lower resolution levels starting at 144p for smoothening playback in areas and countries with limited [[Internet speed]]s, improving compatibility, as well as for the preservation of limited cellular [[data plan]]s. The resolution can be adjusted automatically based on detected connection speed or set manually.<ref>{{cite web |url=https://support.google.com/youtube/answer/91449?hl=en |title=Change the quality of your video – YouTube Help |publisher=Google Inc. |access-date=April 10, 2021 |archive-date=April 10, 2021 |archive-url=https://web.archive.org/web/20210410115130/https://support.google.com/youtube/answer/91449?hl=en |url-status=live }}</ref><ref>{{cite web |last1=Conner |first1=Katie |date=July 1, 2019 |title=Make YouTube videos sharper or load faster |url=https://www.cnet.com/how-to/change-the-quality-of-youtube-videos-on-your-phone-tv-and-laptop/ |publisher=CNET |language=en |access-date=April 10, 2021 |archive-date=April 10, 2021 |archive-url=https://web.archive.org/web/20210410115130/https://www.cnet.com/how-to/change-the-quality-of-youtube-videos-on-your-phone-tv-and-laptop/ |url-status=live }}</ref>

From 2008 to 2017, users could add "annotations" to their videos, such as pop-up text messages and hyperlinks, which allowed for [[interactive video]]s. By 2019, all annotations had been removed from videos, breaking some videos that depended on the feature. YouTube introduced standardized [[Widget (GUI)|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).<ref>{{cite web |title=YouTube launches mobile-friendly "End Screens" feature to keep viewers watching more video |url=https://techcrunch.com/2016/10/26/youtube-launches-mobile-friendly-end-screens-feature-to-keep-viewers-watching-more-video/ |access-date=January 14, 2019 |website=TechCrunch |date=October 26, 2016 |language=en-US |archive-date=March 16, 2021 |archive-url=https://web.archive.org/web/20210316035117/https://techcrunch.com/2016/10/26/youtube-launches-mobile-friendly-end-screens-feature-to-keep-viewers-watching-more-video/ |url-status=live }}</ref><ref>{{cite web |last=Porter |first=Jon |date=November 27, 2018 |title=YouTube annotations will disappear for good in January |url=https://www.theverge.com/2018/11/27/18114581/youtube-annotations-discontinued-january-2019 |access-date=January 14, 2019 |website=The Verge |archive-date=March 16, 2021 |archive-url=https://web.archive.org/web/20210316035117/https://www.theverge.com/2018/11/27/18114581/youtube-annotations-discontinued-january-2019 |url-status=live }}</ref><ref>{{cite web |last=Statt |first=Nick |date=March 16, 2017 |title=YouTube to discontinue video annotations because they never worked on mobile |url=https://www.theverge.com/2017/3/16/14953756/youtube-annotations-feature-discontinue-cards-end-screens |access-date=January 14, 2019 |website=The Verge |archive-date=March 16, 2021 |archive-url=https://web.archive.org/web/20210316035125/https://www.theverge.com/2017/3/16/14953756/youtube-annotations-feature-discontinue-cards-end-screens |url-status=live }}</ref>

In 2018, YouTube became an [[International Standard Name Identifier]] (ISNI) registry, and announced its intention to begin creating ISNI identifiers to uniquely identify the musicians whose videos it features.<ref name="ISNIYouTube1">{{cite web |title=YouTube Adopts ISNI ID for Artists & Songwriters |url=https://www.isni.org/content/youtube-adopts-isni-id-artists-songwriters |access-date=June 1, 2018 |publisher=ISNI |archive-date=June 1, 2018 |archive-url=https://web.archive.org/web/20180601234147/http://www.isni.org/content/youtube-adopts-isni-id-artists-songwriters |url-status=live }}</ref>

Users can verify their account, normally through a mobile phone, to gain the ability to upload videos up to 12 hours in length, as well as produce live streams.<ref name="videolength">[https://www.google.com/support/youtube/bin/answer.py?answer=71673 "Upload videos longer than 15 minutes"] {{Webarchive|url=https://web.archive.org/web/20111102025406/http://www.google.com/support/youtube/bin/answer.py?answer=71673 |date=November 2, 2011 }} YouTube Help. Retrieved July 15, 2017.</ref><ref name="intro to live">[https://support.google.com/youtube/answer/2474026? "Introduction to live streaming"] {{Webarchive|url=https://web.archive.org/web/20171010094743/https://support.google.com/youtube/answer/2474026 |date=October 10, 2017 }} YouTube Help. Retrieved September 22, 2017.</ref> Users who have built sufficient channel history and have a good track record of complying with the site's Community Guidelines will also gain access to these aforementioned features as well.<ref>[https://support.google.com/youtube/answer/9891124#channelhistory "Unlock access to intermediate and advanced features"] {{Webarchive|url=https://web.archive.org/web/20230519090608/https://support.google.com/youtube/answer/9891124#channelhistory |date=May 19, 2023 }} YouTube Help. Retrieved May 19, 2023.</ref> When YouTube was launched in 2005, it was possible to upload longer videos, but a 10-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.<ref>{{cite web |first=Ken |last=Fisher |title=YouTube caps video lengths to reduce infringement |url=https://arstechnica.com/uncategorized/2006/03/6481-2/ |website=[[Ars Technica]] |date=March 29, 2006 |access-date=March 25, 2017 |archive-date=February 26, 2021 |archive-url=https://web.archive.org/web/20210226200136/https://arstechnica.com/uncategorized/2006/03/6481-2/ |url-status=live }}</ref> The 10-minute limit was increased to 15 minutes in July 2010.<ref>{{cite web |first=Josh |last=Lowensohn |title=YouTube bumps video limit to 15 minutes |url=https://www.cnet.com/news/youtube-bumps-video-limit-to-15-minutes/ |publisher=[[CNET]] |date=July 29, 2010 |access-date=March 25, 2017 |archive-date=March 8, 2021 |archive-url=https://web.archive.org/web/20210308013646/https://www.cnet.com/news/youtube-bumps-video-limit-to-15-minutes/ |url-status=live }}</ref> Videos can be at most 256 [[gigabyte|GB]] in size or 12 hours, whichever is less.<ref name="videolength" /> {{Anchor|closed captioning}}{{As of|2021}}, automatic [[Closed captioning|closed captions]] using [[speech recognition]] technology when a video is uploaded are available in 13 languages, and can be [[machine translation|machine-translated]] during playback.<ref>{{cite web |url=https://www.androidheadlines.com/2021/05/youtube-automatic-translation-feature.html |title=YouTube Automatic Translation Feature Rolls Out For Some Users |date=May 6, 2021 |website=Android Headlines |first=Vinay |last=Patel |access-date=December 8, 2021 |archive-date=April 7, 2023 |archive-url=https://web.archive.org/web/20230407034654/https://www.androidheadlines.com/2021/05/youtube-automatic-translation-feature.html |url-status=live }}</ref>

YouTube also offers manual closed captioning as part of its creator studio.<ref name="captioning">{{cite web |title=Adding Captions to YouTube Videos |publisher=[[University of Washington]] |url=https://www.washington.edu/accessibility/videos/youtube/ |access-date=September 4, 2016 |author-link=University of Washington |archive-date=September 11, 2016 |archive-url=https://web.archive.org/web/20160911154901/http://www.washington.edu/accessibility/videos/youtube/ |url-status=dead}}</ref> YouTube formerly offered a 'Community Captions' feature, where viewers could write and submit captions for public display upon approval by the video uploader, but this was deprecated in September 2020.<ref name="community captions">{{cite web |title=Saying Goodbye to YouTube's Community Contributions feature after September 28, 2020 |publisher=Google Inc. |url=https://support.google.com/youtube/thread/61967856?hl=en |access-date=June 8, 2022 |archive-date=April 22, 2023 |archive-url=https://web.archive.org/web/20230422085739/https://support.google.com/youtube/thread/61967856?hl=en |url-status=live }}</ref>

YouTube accepts the most common [[Digital container format|container formats]], including [[MP4 file format|MP4]], [[Matroska]], [[Flash Video|FLV]], [[Audio Video Interleave|AVI]], [[WebM]], [[3GP and 3G2|3GP]], [[MPEG program stream|MPEG-PS]], and the [[QuickTime File Format]]. Some intermediate video formats (i.e., primarily used for professional video editing, not for final delivery or storage) are also accepted, such as [[Apple ProRes|ProRes]].<ref>{{cite web |title=Supported YouTube file formats – YouTube Help |url=https://support.google.com/youtube/troubleshooter/2888402?hl=en |access-date=November 24, 2020 |publisher=Google Inc. |archive-date=March 14, 2021 |archive-url=https://web.archive.org/web/20210314162748/https://support.google.com/youtube/troubleshooter/2888402?hl=en |url-status=live }}</ref> YouTube provides recommended encoding settings.<ref>{{cite web |title=Recommended upload encoding settings – YouTube Help |url=https://support.google.com/youtube/answer/1722171 |access-date=November 24, 2020 |publisher=Google Inc. |archive-date=February 2, 2021 |archive-url=https://web.archive.org/web/20210202163705/https://support.google.com/youtube/answer/1722171 |url-status=live }}</ref>

Each video is identified by an eleven-character [[case-sensitive]] alphanumerical [[Base64#URL applications|Base64]] string in the [[Uniform Resource Locator]] (URL) which can contain letters, digits, an underscore (<code>_</code>), and a dash (<code>-</code>).<ref>{{cite web |title=Here's Why YouTube Will Practically Never Run Out of Unique Video IDs |url=https://www.mentalfloss.com/article/77598/heres-why-youtube-will-never-run-out-unique-video-ids |website=mentalfloss.com |access-date=December 27, 2021 |language=en |date=March 23, 2016 |archive-date=December 27, 2021 |archive-url=https://web.archive.org/web/20211227003053/https://www.mentalfloss.com/article/77598/heres-why-youtube-will-never-run-out-unique-video-ids |url-status=live }}</ref>

In 2018, YouTube added a feature called ''Premiere'' which displays a notification to the user mentioning when the video will be available for the first time, like for a live stream but with a prerecorded video. When the scheduled time arrives, the video is aired as a live broadcast with a two-minute countdown. Optionally, a premiere can be initiated immediately.<ref>{{cite web |url=https://www.howtogeek.com/367588/what-are-youtube-premiers-and-how-do-you-use-them/ |title=What are YouTube Premieres, and How Do You Use Them? |date=October 26, 2018 |access-date=June 23, 2021 |archive-date=June 24, 2023 |archive-url=https://web.archive.org/web/20230624013022/https://www.howtogeek.com/367588/what-are-youtube-premiers-and-how-do-you-use-them/ |url-status=live }}</ref>

==== Quality and formats ====

YouTube originally offered videos at only one quality level, displayed at a resolution of 320×240 [[pixel]]s using the [[Sorenson codec|Sorenson Spark]] codec (a variant of [[H.263]]),<ref name="incomplete-h263">{{cite web |url=https://www.kaourantin.net/2005/08/quest-for-new-video-codec-in-flash-8.html |title=The quest for a new video codec in Flash 8 |first=Tinic |last=Uro |quote=We went this route before with Sorenson Spark which is an incomplete implementation of H.263 and it bit us badly when trying to implement certain solutions. |date=August 13, 2005 |access-date=January 27, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20090206142709/https://kaourantin.net/2005/08/quest-for-new-video-codec-in-flash-8.html |archive-date=February 6, 2009}}</ref><ref name="flash-video">{{cite web |url=https://download.macromedia.com/f4v/video_file_format_spec_v10_1.pdf |title=Adobe Flash Video File Format Specification Version 10.1 |publisher=Adobe Systems Incorporated |page=72 |quote=Sorenson H.263 |year=2010 |access-date=January 27, 2011 |archive-date=December 19, 2011 |archive-url=https://web.archive.org/web/20111219144646/http://download.macromedia.com/f4v/video_file_format_spec_v10_1.pdf |url-status=live }}</ref> with mono MP3 audio.<ref>{{cite web |url=https://www.sorensonmedia.com/news/?n=379 |title=Market Demand for Sorenson Media's Sorenson Spark Video Decoder Expands Sharply |publisher=Sorenson Media |date=June 2, 2009 |access-date=July 31, 2009 |archive-url=https://web.archive.org/web/20090827160021/https://www.sorensonmedia.com/news/?n=379 |archive-date=August 27, 2009 |url-status=dead}}</ref> In June 2007, YouTube added an option to watch videos in [[3GP and 3G2|3GP]] format on mobile phones.<ref>{{cite web |url=https://www.downloadsquad.com/2007/06/17/youtube-mobile-goes-live/ |title=YouTube Mobile goes live |date=June 17, 2007 |access-date=August 11, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20070620083032/https://www.downloadsquad.com/2007/06/17/youtube-mobile-goes-live/ |archive-date=June 20, 2007}}</ref> In March 2008, a high-quality mode was added, which increased the resolution to 480×360 pixels.<ref>{{cite web |title=YouTube Videos in High Quality |url=https://youtube.googleblog.com/2008/03/youtube-videos-in-high-quality.html |website=Official YouTube Blog |date=March 14, 2008 |access-date=March 25, 2017 |archive-date=November 11, 2020 |archive-url=https://web.archive.org/web/20201111220719/https://youtube.googleblog.com/2008/03/youtube-videos-in-high-quality.html |url-status=live }}</ref> In December 2008, [[720p]] [[high-definition video|HD]] support was added. At the time of the 720p launch, the YouTube player was changed from a [[4:3]] [[aspect ratio (image)|aspect ratio]] to a [[widescreen]] [[16:9]].<ref>{{cite web |first=Josh |last=Lowensohn |title=YouTube videos go HD with a simple hack |url=https://www.cnet.com/news/youtube-videos-go-hd-with-a-simple-hack/ |publisher=[[CNET]] |date=November 20, 2008 |access-date=March 25, 2017 |archive-date=January 6, 2021 |archive-url=https://web.archive.org/web/20210106152302/https://www.cnet.com/news/youtube-videos-go-hd-with-a-simple-hack/ |url-status=live }}</ref> 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 resolution|4K]] format, which allows a resolution of up to 4096×3072 pixels.<ref>{{cite web |first=Ramesh |last=Sarukkai |title=What's bigger than 1080p? 4K video comes to YouTube |url=https://youtube.googleblog.com/2010/07/whats-bigger-than-1080p-4k-video-comes.html |website=Official YouTube Blog |date=July 9, 2010 |access-date=March 25, 2017 |archive-date=November 12, 2020 |archive-url=https://web.archive.org/web/20201112041523/https://youtube.googleblog.com/2010/07/whats-bigger-than-1080p-4k-video-comes.html |url-status=live }}</ref><ref>{{cite web |first=Josh |last=Lowensohn |title=YouTube now supports 4K-resolution videos |url=https://www.cnet.com/news/youtube-now-supports-4k-resolution-videos/ |publisher=[[CNET]] |date=July 9, 2010 |access-date=March 25, 2017 |archive-date=August 11, 2019 |archive-url=https://web.archive.org/web/20190811145936/https://www.cnet.com/news/youtube-now-supports-4k-resolution-videos/ |url-status=live }}</ref> In July 2010, support for [[2160p]] UHD was added, with the videos playing at 3840 × 2160 pixels.<ref>{{cite web |title=YouTube Announces Partner Grants Program, Support For 4K Video Resolution |url=https://techcrunch.com/2010/07/09/youtube-partner-program-4k/ |website=TechCrunch |access-date=December 27, 2021 |date=July 9, 2010 |archive-date=December 27, 2021 |archive-url=https://web.archive.org/web/20211227010116/https://techcrunch.com/2010/07/09/youtube-partner-program-4k/ |url-status=live }}</ref> In June 2014, YouTube began to deploy support for [[high frame rate]] videos up to 60 [[frames per second]] (as opposed to 30 before), becoming available for user uploads in October. YouTube stated that this would enhance "motion-intensive" videos, such as [[video game]] footage.<ref>{{cite news |last=Brunner |first=Grant |date=June 27, 2014 |title=Will 60fps YouTube videos force game developers to prioritize frame rate? |url=https://www.extremetech.com/gaming/185454-will-60fps-youtube-videos-force-game-developers-to-prioritize-frame-rate |access-date=November 14, 2019 |website=ExtremeTech |archive-date=March 8, 2021 |archive-url=https://web.archive.org/web/20210308090441/https://www.extremetech.com/gaming/185454-will-60fps-youtube-videos-force-game-developers-to-prioritize-frame-rate |url-status=live }}</ref><ref>{{cite web |url=https://www.theverge.com/2014/10/29/7121143/youtube-adds-support-for-60fps-video-playback |title=YouTube now supports 60fps playback, and video games look amazing |last=Welch |first=Chris |date=October 29, 2014 |website=The Verge |language=en |access-date=November 14, 2019 |archive-date=March 8, 2021 |archive-url=https://web.archive.org/web/20210308101734/https://www.theverge.com/2014/10/29/7121143/youtube-adds-support-for-60fps-video-playback |url-status=live }}</ref><ref>{{cite news |url=https://www.theguardian.com/technology/2014/jun/27/battlefield-hardline-youtube-trailers-games |title=Battlefield Hardline ushers in era of smooth YouTube trailers |work=[[The Guardian]] |date=June 27, 2014 |access-date=June 29, 2014 |first=Keith |last=Stuart |archive-date=March 8, 2021 |archive-url=https://web.archive.org/web/20210308103930/https://www.theguardian.com/technology/2014/jun/27/battlefield-hardline-youtube-trailers-games |url-status=live }}</ref><ref>{{cite web |first=Greg |last=Kumparak |title=YouTube Can Now Play Videos at a Buttery 60 Frames Per Second |url=https://techcrunch.com/2014/10/29/60-fps-youtube/ |website=[[TechCrunch]] |publisher=[[AOL]] |date=October 29, 2014 |access-date=March 26, 2017 |archive-date=February 24, 2021 |archive-url=https://web.archive.org/web/20210224160242/https://techcrunch.com/2014/10/29/60-fps-youtube/ |url-status=live }}</ref> In June 2015, support for [[8K resolution]] was added, with the videos playing at 7680×4320 pixels.<ref>{{cite news |url=https://mashable.com/2015/06/10/youtube-8k-video/ |title=You can watch an 8K video on YouTube – in theory |publisher=MashableUK |date=June 10, 2015 |access-date=July 2, 2015 |first=Stan |last=Schroeder |archive-date=July 3, 2015 |archive-url=https://web.archive.org/web/20150703043235/http://mashable.com/2015/06/10/youtube-8k-video/ |url-status=live }}</ref> In November 2016, support for [[High-dynamic-range video|HDR video]] was added which can be encoded with [[hybrid log–gamma]] (HLG) or [[perceptual quantizer]] (PQ).<ref>{{cite web |first1=Steven |last1=Robertson |first2=Sanjeev |last2=Verma |title=True colors: adding support for HDR videos on YouTube |url=https://youtube.googleblog.com/2016/11/true-colors-adding-support-for-hdr.html |website=Official YouTube Blog |date=November 7, 2016 |access-date=March 25, 2017 |archive-date=June 14, 2020 |archive-url=https://web.archive.org/web/20200614154512/https://youtube.googleblog.com/2016/11/true-colors-adding-support-for-hdr.html |url-status=live }}</ref> HDR video can be encoded with the [[Rec. 2020]] color space.<ref>{{cite web |title=Upload High Dynamic Range (HDR) videos |url=https://support.google.com/youtube/answer/7126552 |website=YouTube Help |access-date=March 25, 2017 |archive-date=February 3, 2021 |archive-url=https://web.archive.org/web/20210203175756/https://support.google.com/youtube/answer/7126552 |url-status=live }}</ref>

YouTube videos are available in a range of quality levels. Viewers only indirectly influence the video quality. In the mobile apps, users choose between "Auto", which adjusts resolution based on the internet connection, "High Picture Quality" which will prioritize playing high-quality video, "Data saver" which will sacrifice video quality in favor of low data usage and "Advanced" which lets the user choose a stream resolution.<ref>{{cite web |date=April 25, 2021 |title=How to adjust adjust video quality on YouTube |url=https://indianexpress.com/article/technology/tech-news-technology/youtube-new-video-quality-settings-explained-7287426/ |access-date=May 30, 2021 |website=The Indian Express |language=en |archive-date=June 2, 2021 |archive-url=https://web.archive.org/web/20210602215246/https://indianexpress.com/article/technology/tech-news-technology/youtube-new-video-quality-settings-explained-7287426/ |url-status=live }}</ref> On desktop, users choose between "Auto" and a specific resolution.<ref>{{cite web |title=Change the quality of your video – YouTube Help |url=https://support.google.com/youtube/answer/91449?hl=en&ref_topic=9257411 |access-date=December 29, 2021 |publisher=Google Inc. |archive-date=December 29, 2021 |archive-url=https://web.archive.org/web/20211229191924/https://support.google.com/youtube/answer/91449?hl=en&ref_topic=9257411 |url-status=live }}</ref> It is not possible for the viewer to directly choose a higher [[bitrate]] (quality) for any selected resolution.

Since 2009, viewers have had the ability to watch 3D videos.<ref>{{cite web |date=July 21, 2009 |title=YouTube in 3D |url=https://www.youtube.com/watch?v=5ANcspdYh_U |archive-url=https://ghostarchive.org/varchive/youtube/20211221/5ANcspdYh_U |archive-date=December 21, 2021 |url-status=live |access-date=August 3, 2009 |via=YouTube}}{{cbignore}}</ref> In 2015, YouTube began natively supporting [[360-degree video]]. Since April 2016, it allowed live streaming 360° video, and both normal and 360° video at up to 1440p, and since November 2016 both at up to 4K (2160p) resolution.<ref>{{cite news |last=Bonnington |first=Christina |date=March 13, 2015 |title=You Can Now Watch and Upload 360-Degree Videos on YouTube |language=en-US |magazine=Wired |url=https://www.wired.com/2015/03/youtube-360-degree-video/ |access-date=May 10, 2021 |issn=1059-1028 |archive-date=July 9, 2016 |archive-url=https://web.archive.org/web/20160709080447/http://www.wired.com/2015/03/youtube-360-degree-video/ |url-status=live }}</ref><ref name="Verge 2016" /><ref>{{cite web |url=https://youtube-eng.googleblog.com/2016/04/new-youtube-live-features-live-360.html |title=New YouTube live features: live 360, 1440p, embedded captions, and VP9 ingestion |website=googleblog.com |publisher=YouTube Engineering and Developers Blog |access-date=December 26, 2021 |language=en |date=April 19, 2016 |archive-date=December 1, 2021 |archive-url=https://web.archive.org/web/20211201205447/https://youtube-eng.googleblog.com/2016/04/new-youtube-live-features-live-360.html |url-status=dead}}</ref> Citing the limited number of users who watched more than 90-degrees, it began supporting an alternative stereoscopic video format known as VR180 which it said was easier to produce,<ref>{{cite news |title=YouTube's "VR180" format cuts down on VR video's prohibitive requirements |language=en-us |work=Ars Technica |url=https://arstechnica.com/gadgets/2017/06/youtubes-vr180-format-makes-vr-video-more-accessible/ |access-date=September 26, 2017 |archive-date=March 16, 2021 |archive-url=https://web.archive.org/web/20210316035205/https://arstechnica.com/gadgets/2017/06/youtubes-vr180-format-makes-vr-video-more-accessible/ |url-status=live }}</ref> which allows users to watch any video using virtual reality headsets.<ref>{{cite web |last=Broida |first=Rick |title=Watch any YouTube video in VR mode |url=https://www.cnet.com/how-to/watch-any-youtube-video-in-vr-mode/ |access-date=May 10, 2021 |publisher=CNET |language=en |archive-date=May 11, 2021 |archive-url=https://web.archive.org/web/20210511133658/https://www.cnet.com/how-to/watch-any-youtube-video-in-vr-mode/ |url-status=live }}</ref>

In response to increased viewership during the COVID-19 pandemic, YouTube temporarily downgraded the quality of its videos.<ref>{{cite news |title=YouTube, Amazon and Netflix cut picture quality in Europe |url=https://www.ft.com/content/70333747-f180-4887-8a26-27ab6b230299 |access-date=March 20, 2020 |work=Financial Times |date=March 20, 2020 |last1=Espinoza |first1=Javier |last2=Fildes |first2=Nic |last3=Murphy |first3=Hannah |last4=Bradshaw |first4=Tim |archive-date=March 8, 2021 |archive-url=https://web.archive.org/web/20210308010939/https://www.ft.com/content/70333747-f180-4887-8a26-27ab6b230299 |url-status=live }}</ref><ref>{{cite web |last=Alexander |first=Julia |date=March 24, 2020 |title=YouTube is reducing its default video quality to standard definition for the next month |url=https://www.theverge.com/2020/3/24/21192384/youtube-video-quality-reduced-hd-broadband-europe-streaming |access-date=October 20, 2020 |website=The Verge |archive-date=February 1, 2021 |archive-url=https://web.archive.org/web/20210201043737/https://www.theverge.com/2020/3/24/21192384/youtube-video-quality-reduced-hd-broadband-europe-streaming |url-status=live }}</ref> YouTube developed its own chip, called Argos, to help with encoding higher resolution videos in 2021.<ref>{{cite web |last=Shankland |first=Stephen |title=Google supercharges YouTube with a custom video chip |url=https://www.cnet.com/news/google-supercharges-youtube-with-a-custom-video-chip/ |access-date=May 5, 2021 |publisher=CNET |language=en |archive-date=May 5, 2021 |archive-url=https://web.archive.org/web/20210505173316/https://www.cnet.com/news/google-supercharges-youtube-with-a-custom-video-chip/ |url-status=live }}</ref>

In April 2023, YouTube began offering some videos in an enhanced bitrate "[[1080p]] Premium" option for YouTube Premium subscribers on iOS.<ref>{{Cite web |last=Roth |first=Emma |date=April 10, 2023 |title=YouTube is giving Premium subscribers higher-quality video than everyone else |url=https://www.theverge.com/2023/4/10/23677141/youtube-premium-subscribers-higher-quality-video-1080p |access-date=April 10, 2023 |website=The Verge |language=en-US |archive-date=December 10, 2023 |archive-url=https://web.archive.org/web/20231210124330/https://www.theverge.com/2023/4/10/23677141/youtube-premium-subscribers-higher-quality-video-1080p |url-status=live }}</ref> In August 2023, the feature became available to subscribers on desktop platforms.<ref>{{cite web |last1=Peters |first1=Jay |title=YouTube's 'enhanced' 1080p for Premium subscribers is now available on desktop web |url=https://www.theverge.com/2023/8/4/23820482/youtube-enhanced-bitrate-1080p-premium-desktop-web-living-room |website=The Verge |date=August 4, 2023 |access-date=December 23, 2023 |archive-date=December 7, 2023 |archive-url=https://web.archive.org/web/20231207200835/https://www.theverge.com/2023/8/4/23820482/youtube-enhanced-bitrate-1080p-premium-desktop-web-living-room |url-status=live }}</ref>

In certain cases, YouTube allows the uploader to upgrade the quality of videos uploaded a long time ago in poor quality. One such partnership with [[Universal Music Group]] included remasters of 1,000 music videos.<ref>{{cite web |last=Perez |first=Sarah |title=YouTube partners with Universal to upgrade nearly 1,000 classic music videos to HD |url=https://techcrunch.com/2019/06/19/youtube-partners-with-universal-to-upgrade-nearly-1000-classic-music-videos-to-hd/ |date=June 19, 2019 |access-date=March 9, 2022 |website=TechCrunch |language=en |archive-date=March 9, 2022 |archive-url=https://web.archive.org/web/20220309091746/https://techcrunch.com/2019/06/19/youtube-partners-with-universal-to-upgrade-nearly-1000-classic-music-videos-to-hd/ |url-status=live }}</ref>

==== Live streaming ====
YouTube carried out early experiments with [[live streaming]], including its [[YouTube Live]] event in 2008,<ref>{{cite web|url=http://latimesblogs.latimes.com/babylonbeyond/2008/11/jordan-queen-ra.html|title=JORDAN: Queen Rania receives YouTube award|date=November 15, 2008|access-date=September 10, 2016|archive-date=May 6, 2021|archive-url=https://web.archive.org/web/20210506101452/https://latimesblogs.latimes.com/babylonbeyond/2008/11/jordan-queen-ra.html|url-status=live}}</ref> a concert by [[U2]] in 2009, and a question-and-answer session with US President [[Barack Obama]] in February 2010.<ref name="CNN 2010">{{cite web |url=https://edition.cnn.com/2010/TECH/web/09/13/youtube.livestreaming/index.html?hpt=C2 |title=YouTube testing live streaming |last=Gross |first=Doug |date=September 13, 2010 |publisher=CNN |access-date=September 22, 2017 |archive-date=September 23, 2017 |archive-url=https://web.archive.org/web/20170923002722/http://edition.cnn.com/2010/TECH/web/09/13/youtube.livestreaming/index.html?hpt=C2 |url-status=live }}</ref> These tests had relied on technology from 3rd-party partners, but in September 2010, YouTube began testing its own live streaming infrastructure.<ref name="BBC 2010">{{cite news |url=https://www.bbc.com/news/technology-11282240 |title=YouTube in two-day live video-streaming test |date=September 13, 2010 |newspaper=BBC News |access-date=July 21, 2018 |archive-date=November 10, 2019 |archive-url=https://web.archive.org/web/20191110052422/https://www.bbc.com/news/technology-11282240 |url-status=live }}</ref> In April 2011, YouTube announced the rollout of ''YouTube Live''. The creation of live streams was initially limited to select partners.<ref name="YT Blog 2011">{{cite web |url=https://youtube.googleblog.com/2011/04/youtube-is-going-live.html |title=YouTube is going LIVE |date=April 8, 2011 |website=YouTube Official Blog |access-date=September 22, 2017 |archive-date=September 23, 2017 |archive-url=https://web.archive.org/web/20170923002634/https://youtube.googleblog.com/2011/04/youtube-is-going-live.html |url-status=live }}</ref> It was used for real-time broadcasting of events such as the 2012 Olympics in London.<ref>{{cite magazine |url=https://www.wired.com/2015/08/youtube-sleeping-giant-livestreaming/ |title=YouTube Is the Sleeping Giant of Livestreaming |last=Pierce |first=David |magazine=Wired |language=en-US |access-date=September 22, 2017 |date=August 17, 2015 |archive-date=November 8, 2020 |archive-url=https://web.archive.org/web/20201108112508/https://www.wired.com/2015/08/youtube-sleeping-giant-livestreaming/ |url-status=live }}</ref> In October 2012, more than 8&nbsp;million people watched [[Felix Baumgartner]]'s [[Red Bull Stratos|jump from the edge of space]] as a live stream on YouTube.<ref>{{cite news |url=https://www.newsday.com/news/nation/felix-baumgartner-s-jump-from-space-s-edge-watched-by-millions-1.4115479 |title=Felix Baumgartner's jump from space's edge watched by millions |agency=Associated Press |date=October 15, 2012 |access-date=October 15, 2012 |url-status=dead |archive-url=https://web.archive.org/web/20121018071353/https://www.newsday.com/news/nation/felix-baumgartner-s-jump-from-space-s-edge-watched-by-millions-1.4115479 |archive-date=October 18, 2012}}</ref>

In May 2013, creation of live streams was opened to verified users with at least 1,000 subscribers; in August of the same year the number was reduced to 100 subscribers,<ref name="Verge 2013">{{cite web |url=https://www.theverge.com/2013/8/3/4586624/youtube-live-streaming-now-available-to-channels-with-100-subscribers |title=YouTube opens up live streaming to anyone with 100 or more subscribers |last=Blagdon |first=Jeff |date=August 3, 2013 |website=[[The Verge]] |access-date=September 22, 2017 |archive-date=November 12, 2020 |archive-url=https://web.archive.org/web/20201112025730/http://www.theverge.com/2013/8/3/4586624/youtube-live-streaming-now-available-to-channels-with-100-subscribers |url-status=live }}</ref> and in December the limit was removed.<ref name="MacNN 2013">{{cite web |url=https://www.macnn.com/articles/13/12/13/youtube.abandons.100.subscriber.limit.for.live.streaming/ |title=YouTube opens live streaming for all verified accounts |date=December 13, 2013 |website=MacNN |access-date=September 22, 2017 |archive-date=September 23, 2017 |archive-url=https://web.archive.org/web/20170923003125/http://www.macnn.com/articles/13/12/13/youtube.abandons.100.subscriber.limit.for.live.streaming/ |url-status=dead}}</ref> 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,<ref name="Ars Technica 2017-02-08">{{cite web |url=https://arstechnica.com/information-technology/2017/02/youtube-now-lets-creators-with-10000-subscribers-live-stream-video-on-mobile/ |title=YouTube now lets creators with 10,000 subscribers live-stream video on mobile |last=Palladino |first=Valentina |date=February 8, 2017 |website=[[Ars Technica]] |access-date=September 22, 2017 |archive-date=November 12, 2020 |archive-url=https://web.archive.org/web/20201112031216/https://arstechnica.com/information-technology/2017/02/youtube-now-lets-creators-with-10000-subscribers-live-stream-video-on-mobile/ |url-status=live }}</ref> but as of mid-2017 it has been reduced to 100 subscribers.<ref name="create live">[https://support.google.com/youtube/answer/2853700 "Create a live stream"] {{Webarchive|url=https://web.archive.org/web/20171010095216/https://support.google.com/youtube/answer/2853700 |date=October 10, 2017 }} YouTube Help. Retrieved September 22, 2017.</ref> Live streams support HDR, can be up to 4K resolution at 60 fps, and also support 360° video.<ref name="Verge 2016">{{cite web |url=https://www.theverge.com/2016/11/30/13783272/youtube-update-4k-live-streaming-support-360-video |title=YouTube now supports 4K live-streaming for both 360-degree and standard video |last=Garun |first=Natt |date=November 30, 2016 |website=[[The Verge]] |access-date=September 23, 2017 |archive-date=December 9, 2020 |archive-url=https://web.archive.org/web/20201209043847/https://www.theverge.com/2016/11/30/13783272/youtube-update-4k-live-streaming-support-360-video |url-status=live }}</ref><ref>{{cite web |last=Porter |first=Jon |date=December 8, 2020 |title=YouTube live streams now support HDR |url=https://www.theverge.com/2020/12/8/22162889/youtube-live-stream-hdr-support |access-date=May 10, 2021 |website=The Verge |language=en |archive-date=May 10, 2021 |archive-url=https://web.archive.org/web/20210510172849/https://www.theverge.com/2020/12/8/22162889/youtube-live-stream-hdr-support |url-status=live }}</ref>