speed up youtube videos
Windows: Ctrl + Shift + J
macOS: Command + Option + J
Copy and paste this into the console:
document.getElementsByTagName("video")[0].playbackRate = x
Replace x with the speed you want the video to be played at, and enter/return.
Works for speeds with decimals too, so you can try 3, 0.1, 200, etc.
Cheers!