I've tried half a dozen volume boost extensions to make quiet youtube videos louder, and this is the only one that worked immediately on installation. (firefox 60.9.0esr on linux)

Test

I've not used it that much (just 2 times), but it does what is supposed to. I can increase the max volume so it is now a pleasure to listen youtube when songs are silent even at max volume!

It's a very nice and clean tool. It will be even better if it can persist the settings trough page refreshes.

Nice little tool that dose exactly what it says it dose with no fluff.

id give ya a million bucks if I could ty

Very useful when it's needed

fantastisch.fantastic.first item that help. i can hear youtube videos. great.

Király.