Great stuff!

Could you add support for shorts as well?

Works fantastic

It marks clearly watched videos. It's easy to export and import watched videos from a browser to another.

I can't even remember what Youtube is like without this addon. Incredible work.

Very useful, nicely structured, would be 5 stars if
1) it didn't slow YT videos to an almost complete lag; (database 4495)
---Would marking the text (purple or red) instead of the image use less resources?
---I have many unloaded tabs of videos, is something collating all those unloaded tabs each time?
2) it said when each option marks a video- do any mark when they are queued? When do the YT options mark them? When does history matk them
3) once you have a collection in memory, which ones are needed to update it?

Very useful tool !
Thank you

Works great in standard desktop mode, does not work when viewing youtube from the mobile feed, on a computer and a regular browser....

Works even on different computers. You only have to log in to your gmail and you see all the marks videos you´ve watched on another computer

Handy extension that actually fills a real need rather than just adding fluff! Two nice additional features would be 1) The ability to mark a video "unwatched" and 2) The ability to set a threshold (in seconds, maybe?) after which the video is marked "watched". Right now, simply loading the video (but not even playing it) marks the thumbnail as watched. Great extension nonetheless.

extremely useful and works perfectly. the only thing i miss is an easy way to regulate how much the thumbnails of watched videos get dimmed. otherwise an A+ extension that i hope lives forever.

Please add an option to have the extension hide the mark the videos as not interested or hide them in some way please.