System-wide audio equalizer for Windows, powered by Equalizer APO.
A beautiful, modern web GUI that controls Equalizer APO's 15-band graphic EQ in real-time.
- 15-band Graphic EQ (25Hz - 16kHz) with custom fader controls
- Real-time frequency curve visualization
- 20+ presets organized by category (General, Genre, Bass, Edifier Monitors)
- Edifier monitor profiles based on Spinorama measurements (R1280T, R1700BT, MR4, MR3BT, M60)
- Auto Pre-Amp calculates safe preamp to prevent clipping
- Clipping indicator shows peak headroom in real-time
- Smooth animations when switching presets (350ms ease-out cubic)
- Keyboard shortcuts (1-9 presets, 0=Flat, R=Reset, A=Auto, E=Toggle)
- System-wide - equalizes ALL audio output (music, videos, games, everything)
- Starts with Windows - runs silently in background
- Zero latency - Equalizer APO works at the driver level
- Windows 10/11
- Equalizer APO installed
- Node.js 18+ (for development)
- Install Equalizer APO and select your audio device
- Clone this repo
- Run
npm install - Run
npm start - Open
http://localhost:3847
The app runs a lightweight Express server that reads/writes Equalizer APO's config.txt file. Changes are applied instantly - no restart needed.
The EQ settings persist even when the app is closed, because Equalizer APO runs as a Windows audio driver.
| Key | Action |
|---|---|
1-9 |
Load preset by number |
0 |
Flat (bypass) |
R |
Reset all bands to 0 |
A |
Auto Pre-Amp (prevent clipping) |
E |
Toggle EQ on/off |
- Backend: Node.js + Express (reads/writes Equalizer APO config)
- Frontend: Vanilla HTML/CSS/JS (no frameworks, ~30KB)
- Fonts: JetBrains Mono + Outfit (Google Fonts)
- Audio Engine: Equalizer APO (system driver)
MIT