Free per-app volume control for keyboard knobs & hotkeys — Windows
Control the volume of individual apps independently. Turn one knob for your game, another for Discord, another for your browser — all at the same time.
Requires: Windows 10 or 11 (64-bit)
KnobMixer is a new app and isn't yet recognized by Microsoft SmartScreen, so Windows may show a "Windows protected your PC" screen the first time you run the installer. This is normal for new apps that aren't code-signed yet — it isn't a virus warning.
To continue: click More info → Run anyway.
If your knob already controls your PC volume, you're 30 seconds away:
- Open KnobMixer and enable Hardware Knob at the top of the main window.
- Set your Cycle key.
- Add your apps to whichever groups you want.
That's it. For full customization (custom keys, multiple knobs), follow the guide below — or just run the built-in setup guide that opens on first launch.
Step 1 — Program your keyboard in your keyboard's software (skip if your knob can't be remapped — see below)
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1-Knob Mode
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Multiple Knobs Mode
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💡 Map your knob to spare keys you don't use elsewhere (F13–F24 are ideal) so nothing clashes with other apps. Avoid keys like F12, which some apps use (e.g. Steam screenshots).
💡 In Multiple Knobs mode, set the music knob's click to Play/Pause in your keyboard software — it'll pause the song instead of muting the audio.
Step 2 — Choose your mode
- 1-Knob mode — one knob controls all groups; press the Cycle key to switch between them.
- Multiple Knobs — each group has its own hotkeys. Best if you have 2 or more knobs.
Step 3 — Set your hotkeys
In KnobMixer, assign the keys from Step 1 to your groups. In 1-Knob mode, the shared keys appear above the groups on the main window.
Step 4 — Add your apps
Click Edit on each group and add the apps it should control (e.g. spotify, discord, cs2). Any app that's currently playing shows up in the list for one-click adding.
Enable Hardware Knob in Settings → 1-Knob Mode. KnobMixer intercepts the system volume keys your knob sends and redirects them to your active group — your Windows system volume stays untouched.
- Control multiple apps at once
- Works in fullscreen games
- Instant response, lightweight (~0% CPU idle)
- No ads, no tracking, no login
KnobMixer works with any hotkey combination — keyboard shortcuts, stream deck keys, or mouse buttons.
License: Business Source License 1.1 — free for personal use. Commercial use or competing products require written permission.
