Google uses the VP9 codec technology on YouTube to reduce the size of the video. On most platforms, users can watch videos with 4K-level clarity.
However, Apple does not support the VP9 codec in the iOS system, so users can only watch 1080P videos at most, and Apple is not ready to change until iOS 14.0.
In the latest iOS 14 beta, Apple has added support for the VP9 codec, and Safari also supports the VP8-derived WebP image format.
“iPhone 11 / iPhone 11 Max / iPhone 11R / iOS 13 Concept” by Ran Avni is licensed under CC BY-NC-ND 4.0
Google’s codec is not supported before, so iPhone, iPad, and Apple TV users can only watch 1080P resolution when watching YouTube videos.
After adding codec support, you can now watch up to 4K HDR video provided by YouTube. Users can switch the video by clicking the resolution when watching the video.
Users who have used iOS 14 betas and are used to watching YouTube videos can try it now. Remember to look for 4K-level videos for testing.
If the video itself does not have 4K resolution, the corresponding option will not pop up. If you test it, you can search YouTube for 4K and you can see a lot of videos.