Started up YouTube today and the thumbnails on my 32 inch monitor went from around 6 or so per line to 3 per line. So I did a search and it seems this has been happening on YouTube lately and for Firefox YouTube Tweaks was suggested.

I installed it and was able to get the number of thumbnails back to 6 and even was able to increase it more, I settled on 8.

Only thing I couldn't seem to fix was Shorts are still too large, but I may have missed something.

There are also a lot more tweaks like removing shorts, which I have been playing around with.

Woke up to see only 2 videos per row on a 55 inch tv and only 4 when zoomed out to 30% which is just inconceivable that someone thought that was a good idea.
Thank you Pedro you are the goat.

could you add functions to tweaks how many shorts and posts per row (with options like max number and min width)?

The other day my YT started showing only 4 videos per line on a 4k screen set to 2560x1440, with even more space available if I wanted. I jumped onto Reddit and found this. It didn't work at all and gave up. But today I decided to look again and saw that Pedro released another version and recognized that YT had changed something fundamental. With that it is all fixed. I set it to 6 icons per line just like it was before YT "fixed" things. I'll have to explore the other settings too, there were too many to get through.

Honestly this is such a fantastic extension, one gripe though and hoping for QOL change, hopefully you can give us the ability to be able to move the popup player with just dragging and grab the corners to resize as well.

Exactly what I needed. Opened youtube for it to only show me two videos with giant thumbnails on the front page, and I thought this is ridiculous. Now with this I have 10 videos showing instead, so much better. The only thing I have an issue with is that the "hide livestreams" option doesn't seem like it's working, unless I'm misunderstanding the purpose. I'm telling it to hide completed livestreams (and also tried hiding both ongoing and completed) and it doesn't seem to hide them. I still get many of the "streamed 12 hours ago" videos in my subscriotion feed.

Almost perfect ...