This script helps you watch YouTube videos in Premium HD quality where it's supported for free (without a subscription).

For example, here or here.

The approach is similar to how yt-dlp does it: get the HLS manifest from the iOS player response.

Written by pepeloni-away and originally shared on Reddit. I'm just reposting it here so more people can find it.

Note: I set onlyOnPremiumAvailable to true because I assume that most people are logged in and don't want the script to affect other videos without Premium HD. You can adjust these variables yourself how you want.