CAUTION:

This script will alter your site preference setting localStorage['yt-player-av1-pref'].

The modified setting will remain even if you have disabled or uninstalled the script.

Browser Support:

https://caniuse.com/?search=AV1%20video%20format

• Chrome 70+, Firefox 67+, Opera 57+: supported
• Edge, Safari: NOT supported

Tests:

• 4K Video: https://www.youtube.com/watch?v=dFlDRhvM4L0
• 1080P: https://www.youtube.com/watch?v=iFIXi6zzCls
• 720P: https://www.youtube.com/watch?v=JLH7_ad0BrI
• 2012 old video: https://www.youtube.com/watch?v=OG6u8CDvpI4

Preview: