Editing & Post-Production
YouTube Studio editor
Also called: Studio editor, YouTube video editor, trim tool, blur tool
Studio's editor works on videos that are already live. You can trim the start or end, cut a section out of the middle, blur faces, add end screens, and replace the audio with a track from YouTube's library. The video keeps its URL, its views and its comments, which is the reason to reach for it rather than re-uploading.
It is limited on purpose. What it is for is the mistake you find after publishing: a name said out loud, a licence problem in the music bed, 40 seconds of dead air at the top.