List of YouTube features
YouTube is an online video sharing platform owned by Google, founded on February 14, 2005, by Steve Chen, Chad Hurley, and Jawed Karim, and headquartered in San Bruno, California, United States. It is the second-most visited website in the world, after Google Search.
It offers different features based on user verification, such as standard or basic features like uploading videos, creating playlists, and using YouTube Music, with limits based on daily activity ; intermediate or additional features like longer videos, live streaming, custom thumbnails, and creating podcasts; advanced features like content ID appeals, embedding live streams, applying for monetization, clickable links, adding chapters, and pinning comments on videos or posts.
As of October 2024 it includes multitask with the improved miniplayer, build, share, and vote on favorite YouTube playlists, set bedtime with Sleep Timer, and an upgrade on YouTube TV.
Video technology
YouTube primarily uses the VP9 and H.264/MPEG-4 AVC video codecs, and the Dynamic Adaptive Streaming over HTTP protocol. By January 2019, YouTube had begun rolling out videos in AV1 format, since then videos which are popular have it. In 2021 it was reported that the company was considering requiring AV1 in streaming hardware in order to decrease bandwidth and increase quality. For stereo, video is usually streamed alongside the Opus or AAC audio codecs. For 5.1 sound, Dolby Digital, Dolby Digital Plus, rarely DTS Express or AAC is used. Additionally, some videos may include Eclipsa audio, which combines Opus with IAMF. Certain music has HE-AAC, which is exclusively available on YouTube Music. Additionally, some videos may have separate audio streams with Dynamic Range Compression and/or Voice Boost.At launch in 2005, viewing YouTube videos on a personal computer required the Adobe Flash Player plug-in to be installed in the browser. MPEG-4 Part 2 streams contained within 3GP containers were also provided for low bandwidth connections. In January 2010, YouTube launched an experimental version of the site that used the built-in multimedia capabilities of Web browsers supporting HTML video. This allowed videos to be viewed without requiring Adobe Flash Player or any other plug-in to be installed. On January 27, 2015, YouTube announced that HTML video would be the default playback method on supported browsers. HTML video streams use Dynamic Adaptive Streaming over HTTP, an HTTP-based adaptive bit-rate streaming solution optimizes the bitrate and quality for the available network.
The platform can serve videos at optionally lower resolution levels starting at 144p for smoother playback in areas and countries with limited Internet speeds, improving compatibility, as well as for the preservation of limited cellular data plans. The resolution can be adjusted automatically based on detected connection speed or set manually.
From 2008 to 2017, users could add "annotations" to their videos, such as pop-up text messages and hyperlinks, which allowed for interactive videos. By 2019, all annotations had been removed from videos, breaking some videos that depended on the feature. YouTube introduced standardized widgets intended to replace annotations in a cross-platform manner, including "end screens".
In 2018, YouTube became an International Standard Name Identifier registry, and announced its intention to begin creating ISNI identifiers to uniquely identify the musicians whose videos it features.
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. 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. 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. The 10-minute limit was increased to 15 minutes in July 2010. Videos can be at most 256 GB in size or 12 hours, whichever is less., automatic closed captions using speech recognition technology when a video is uploaded are available in 13 languages, and can be machine-translated during playback.
YouTube also offers manual closed captioning as part of its creator studio. 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.
YouTube accepts the most common container formats, including MP4, Matroska, FLV, AVI, WebM, 3GP, MPEG-PS, and the QuickTime File Format. Some intermediate video formats are also accepted, such as ProRes. YouTube provides recommended encoding settings.
Each video is identified by an eleven-character case-sensitive alphanumerical Base64 string in the Uniform Resource Locator which can contain letters, digits, an underscore, and a dash.
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.
Quality and formats
YouTube originally offered videos at only one quality level, displayed at a resolution of 320×240 pixels using the Sorenson Spark codec, 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 November 2008, 720p HD support was added. At the time of the 720p launch, the YouTube player was changed from a 4:3 aspect ratio to a widescreen 16:9. 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 July 2010, support for 2160p UHD was added, with the videos playing at 3840 × 2160 pixels. In June 2014, YouTube began to deploy support for high frame rate videos up to 60 frames per second, becoming available for user uploads in October. YouTube stated that this would enhance "motion-intensive" videos, such as video game footage. 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 or perceptual quantizer. HDR video can be encoded with the Rec. 2020 color space.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. On desktop, users choose between "Auto" and a specific resolution. It is not possible for the viewer to directly choose a higher bitrate for any selected resolution.
Since 2009, viewers have had the ability to watch 3D videos. 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 resolution. 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, which allows users to watch any video using virtual reality headsets.
In response to increased viewership during the COVID-19 pandemic, YouTube temporarily downgraded the quality of its videos. YouTube developed its own chip, called "Argos", to help with encoding higher resolution videos in 2021.
In April 2023, YouTube began offering some videos in an enhanced bitrate "1080p Premium" option for YouTube Premium subscribers on iOS. In August 2023, the feature became available to subscribers on desktop platforms.
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.
As of, a feature known as "Super Resolution" began rolling out, using artificial intelligence to upscale older videos to a resolution of up to 1080p.
Live streaming
YouTube carried out early experiments with live streaming, including its YouTube Live event in 2008, 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. 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 the same 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 support HDR, can be up to 4K resolution at 60 fps, and also support 360° video.