It works, also has Import/export feature which seem like a great idea.

Does exactly what it says, and is incredibly useful when I follow my subscription feed.

Thanks for the Addon and for fixing it recently!

please update youtube has done so many changes and it doesn't fully work anymore, it still adds "watched" to the videos but it doesn't fade the thumbnails

edit: ty for fixing It I was already planning to change my rating don't worry ;)

Works great, only thing I'd like to see being added would be that it automatically marks all of your liked videos as watched too, there's a playlist with all of your liked videos maybe you'll be able to use that

Great extension however over the last few days it no longer works for videos in the sidebar or on the main youtube page.

Works on the subscriptions page at least as well on search results.

UPDATE: Unfortunately due to YTs cursor over to play feature, any video that I accidentally cursor over gets marked as viewed, just to be aware
Youtube has started removing the watched indicator / red line on videos, and this not only restores that functionality perfectly, it does it better visually. I definitely recommend it!

unbelievably useful. tyvm.

Still works after Youtube removed Watched indicators from recommendations in the sidebar of video pages. I was able to add my history by scrolling through my watch history, but it will pick up watched videos from your sub box and elsewhere. Thanks for restoring useful functionality that Youtube saw fit to remove.

Great addition to YouTube, adds functionality that YouTube intentionally missed, small feature request - auto hide watched if you mark them to be permanently hidden. In any-case thank you for the work chap!

Really simple and effective since Youtube is very poor at marking what you've already watched. This addon does a great job but the only gripe might be that simply by starting a youtube video and watching a few secs will mark a video as watched and I don't think there is a way to undo/unmark it.

Thanks, i was really looking for something like this, could you add a toggle or something for not seeing watched videos..or maybe rearranging the rest of the thumbnails would be too much. Maybe replace the empty watched video thumbnails with subscription new videos or something. lol i dont know how that would even work..

Been using this addon for years and it has worked great. I've got about 25,000 watched videos in my YouTube Watchmakers database. That is so much more than the 5,000 maximum that YouTube will remember. It would be great if it would add YouTube videos that are watched on other sites like Bing, Just mentioning it, Thanks for the great extension!