Greasy Fork is available in English.
Adds one icon to the YouTube transcript panel. Click it and everything in the transcript is selected so you can copy it instantly.
Effortlessly select the entire YouTube transcript with a single click.
This lightweight userscript adds a "Select All" button to the YouTube transcript panel. Instead of clicking and dragging through thousands of lines of text, simply click the icon, and the entire transcript is instantly highlighted and ready to be copied ($Ctrl+C$ / $Cmd+C$).