The extension is excellent, and its new version, available on Chrome/Brave, is also very good.
Unfortunately, for some reason that the author did not detail, he is not motivated to continue providing updates on Firefox. Help out, Firefox.

Author's quote: "the version 3 will only be available for Firefox if Mozilla changes its review process because after more than 12 years publishing my extension on AMO there are things that I don't accept anymore..."

+ Probably due to a browser update, my extension had broken some important options, so I switched to another one. Now, returning to Firefox and reinstalling the old extension, I noticed that 'Boost Audio' is better in this version, even at level '10', than the updated version on Brave/Chrome. There, the audio already starts losing quality at level '3', making it unviable to use at level '10'.

Great extension the boost volume works wonders, i always wanted something like that to work on my pc as a whole, somehow things sound good on my mobile but not my windows pc even tweaks for youtube extension didn't work like this but this did it in just one click.

I'd like to know what is being used to boost volume? can you please tell me how its done in a way that i can replicate that on my audio equalizer app (Equalizer APO on windows.)so that i can somehow hear things as they should be heard and not have headache to hear things.

I like the app it has those features that can help you at youtube like to make the sound louder or to change the colors. I recommand the extension.

Please update to the same version as Chrome and Edge. This plug-in is really essential.
请更新到与谷歌Chrome浏览器与edge浏览器一样的版本，这个插件必不可少，但是七个月没有更新了

this mod is an absolute essential for me! when it was gone for a few months, i had to make due with a hodgepodge of lesser mods and it was not fun. as of today, though, it seems something has gone a bit wonky because the UI is off center from it's usual and it looks massive and bubbly out of nowhere so it might need a little bit of an update. like, suddenly the icons are in a darker bar and the icons don't fit in it and in fact, the volume booster option is gone. it still works, it's just weird and looks like it shouldn't work

one of my favorite extensions

After last YouTube changes (June/July 2025), control elements and keyboard shortcuts stopped working.
UPD: After the last extension update, all works again! 😊