Hi! Thanks for the feedback, sorry it's not working for you. A few quick questions to help track this down: could you tell me which site(s) you tried it on, whether you've restarted the browser since installing, and what other extensions you have installed? Some extensions can conflict with page audio access, so knowing what else is running would help me narrow it down.

Just wanted to clarify, Volume Master does work on YouTube, but it's capped at 600% (if you choose max volume on YouTube) due to a browser-level limitation that no extension can bypass. If you're not hearing any increase at all, try refreshing the page after installing the extension and then adjusting the slider. Hope that helps!