TabMixer от Emre Eren

TabMixer gives you full control over the volume of each browser tab individually, just like a professional audio mixer.

Key Features:

Individual volume control for each tab (10–150%)
In-page floating volume widget for quick access
Volume boost up to 150% on supported sites
Automatic DRM compatibility (Netflix, Spotify, MUBI, Disney+, etc.)
Per-tab mute/unmute
One-click reset to restore all tabs to defaults
Lightweight and fast — zero dependencies
How It Works:

Click the TabMixer icon to see all audible tabs with volume sliders
A floating speaker icon appears on audio-playing pages for quick volume control
DRM-protected content is detected automatically — no configuration needed
Standard sites support volume boost up to 150% via Web Audio API
DRM sites get safe volume control (10–100%) without interfering with playback
Privacy-First: No tracking, no analytics, no external connections. Everything runs locally in your browser.

Source code: codeberg.org/emreren/TabMixer