Volume Fader од Krummel

Ever had five tabs open and had no idea which one just started blasting an ad at full volume? Fader fixes that.
Click the toolbar icon and you get a clean slider for whatever tab you're on, plus mini sliders for every other open tab — all in one place. Drag to adjust, hit Mute, or boost a quiet tab up to 200% if you need it louder. Close the popup and it just works in the background.
What it does:

Per-tab volume control from 0% to 200%
Volume boost for tabs that are just too quiet
See and control all your open tabs at once
Remembers your settings if you refresh the page
One click to reset everything back to 100%

No accounts. No tracking. No data collected. Everything stays on your machine.