Greasy Fork is available in English.
Scan page for Youtube embeds and urls and replace with Invidious.
< Feedback on Youtube to Invidious
If you know a viable replacement I am happy to experiment with it.
Problem is they're not actually using MutationObserver but instead triggering looking at the whole DOM again every time it changes.
https://www.reddit.com/r/privacy/comments/bi1vg1/psauseinvidioustowatchyoutubevideos_instead/elyh39y/
edit: I'm removing this site from my oAuth again so who knows if I'll orphan this account.
These performance issues should be fixed now, let me know if you still have problems.
They have been fixed.
MutationObserver
Using it results in the browser slowing down. Please use something else instead of it.