After switching to HTML5 for better video load times, YouTube has started tagging videos with 4K content. This tag will show up next to video thumbnails and just like the 'HD' tag, 4K videos would carry a '4K' tag in the same place. While most of us are looking at YouTube through 720p or 1080p screens, YouTube quickly adopted to the 4K standard just two years after it started streaming in HD.
YouTube knows streaming well, with all these years of experience riding with it, they have optimized their back-end streaming servers to match the heavy bandwidth that these 4K videos would require. Today, YouTube has a huge library of 4K videos. A spokesperson even went on record to say that 4K videos tripled last year. With the commercialization of 4K production equipment, more and more people are able to produce content in Ultra-high definition. Smartphones nowadays have the ability to record in 4K at pretty high bit rates for its size, clearly then 4K is not just a marketing stunt, it has started setting itself as the next industry standard beyond 1080p. YouTube says it has recorded peak searches for 4K videos in the last year itself and has streamed many more hours of 4K videos. Smart TV's carry native videos streaming capabilities from YouTube, with regular updates, the YouTube app for such T.V's also features streaming in 4K. This brings 4K streaming out of your personal devices and into the living room. Here is a sample video served to you in 4K :
According to YouTube, what is helping them achieve this is the new VP9 codec that they moved to last year. The VP9 codec became a standard since last year. The last update to the codec was in 2010 with the release of the VP8 codec for enhanced HD video. When VP9 was released, Google knew it would like to have quick adoption. This was marked by the partnerships it announced with hardware vendors like ARM, Intel, Broadcom and Marvell along with consumer electronic giants like Samsung, Toshiba and Sharp. Francisco Varela, global director of platform partnerships at YouTube says that this is all about doing away with the "spinning wheel" of buffering and also reduce the data required to deliver the videos from one end to another.