Prerequisites
This new VP9 codec is only available on the iOS 14 so your iPhone should be running the iOS 14. Since the iOS 14 isn’t out yet, you have to install the beta version of the iOS 14 on your iPhone or iPad. If you don’t want to install the beta version of iOS 14 then you can wait for the final release.
We won’t recommend you to install the iOS 14 beta on your primary phone as well. You can try this on a secondary phone but if you want it on your primary phone then you need to wait for the final iOS 14 release.
How to Play 4K YouTube video on iPhone and iPad
Wrapping up
This is how you can play 4K videos on YouTube on your iPhone or iPad. It is not available to all the iPhone users by now but if you already running the iOS 14 beta version then give it a shot.
