You will need to install a user script manager extension to install this script.
You watch a lot of youtube videos ? Are subscribed to several channels or users ? Get tired of looking for a video you haven't seen yet on an endless page ?
Let's try this script which will add a button to the top right of the screen (in the navbar) to allow you to hide videos already watched (the ones with the 100% progress bar).
Click again on the button, and videos are shown again.
It'll keep your last choice in cookies the following way :
If you just want to enable the feature on every youtube's page, click on the second button. It will override the page' specific value.
You can of course have both button enabled, but it will have the same result.
NO EXTERNAL LIBRARY