The main reason I wanted this extension was to make YouTube stop spamming already watched videos, random playlists and useless shorts.
1) It doesn't block already watched videos, it just makes them less visible by hiding the thumbnail and dimming their links;
2) Sometimes it marks random videos as watched, but I never even clicked their links, even less watched them;
3) It cannot block playlists, as far as I've used it;
4) It blocks shorts successfully AND entirely (not just dim their links), which is good.

Update 23/Feb/2026: It's worse now. The button to hide videos won't even show up. I enabled it, restarted Firefox, and still not there.

On Android versions Firefox The extension does not work

Very slow (even by youtube standards), whatever what the dev will say: sometimes takes almost a minute to load a youtube video, and often will fail to load the full page, with the comments.

Very buggy: again, often failing to load a page fully, the mini-player suddenly not appearing anymore when scrolling down, or among many others, the limiting to H.264 not working reliably (to be fair, it only reliably works with enhanced-h264ify, whichever main youtube extension I use). Even the menu is buggy: the search bar will always cover the link to go back in the menu (so one has to close that search bar again and again), and if used in the extension panel (as opposed to using it pinned), it won't even fit the window properly, lol!

Fortunately, I discovered a little used extension (Tweaks for youtube: only about 3k users, which is baffling), that is great where Improve youtube isn't at all. I tested them all, and that's the only one I'll keep.

was working for a period of time but in the last month any settings used would lag youtube; back button and pause taking forever.
removed extension and youtube stared working again, unfortunate as it was a good addition :/

Please add customize for short video.

チャンネルをブラックリストに登録しても表示されたままで消えてくれない。

The mini player hasnt been working.

Only feature that works is themes.

This extension makes YT lags as hell. I swear to God. I uninstalled it and it went back to normal.

Sick and tired of having features work then break then back again without any real explanation. Almost got to the point to which I was going to switch back to Chrome until I found the extension I was using there finally got ported to Firefox.

A valiant effort, but plagued by too many bugs.

Unfortunately.it doesn't work on android

de fato nenhum supera o falecido youtube enhancer... esse até tinha boa proposta e algumas opções apesar de bem cru, mas o mais importante não cumpriu, que é bloquear o lixo cibernético (refiro a propagandas)

Uw gegevens voor websites in het ‘genoemde’ domein benaderen

De extensie kan de inhoud van webpagina’s die u in het opgegeven domein bezoekt lezen, evenals gegevens die u in deze webpagina’s invoert, zoals gebruikersnamen en wachtwoorden.

now I can't use free scroll