Add Chorus to Audio
Upload audio and thicken it with short modulated delay voices. Tune voices, delay, depth, rate and decay, then export mp3, wav, ogg, flac or m4a.
Add chorus to audio in your browser
A chorus effect thickens a sound by mixing the dry signal with short delayed copies whose delay time moves slightly. That tiny modulation makes a vocal, synth, guitar, or pad feel wider and richer than a single track. This tool wraps ffmpeg's chorus filter with friendly controls instead of raw filter text.
Use Voices for how many delayed copies are added, Delay for the base delay time, Depth for how far the modulation moves, Rate for how fast it moves, and Voice level for the wet delayed copies. The page processes locally in your browser and exports mp3, wav, ogg, flac, or m4a.
Worked example
For a plain mono guitar part, start with the Classic Chorus preset: 2 voices, 50 ms delay, 2 ms depth, 0.4 Hz rate, and 0.4 voice level. For a wider synth pad, try Lush Ensemble with 4 voices, 55 ms delay, 5 ms depth, and a 0.55 voice level. For a moving shimmer, increase the rate above 2 Hz and keep the level moderate.
Control guide
- Voices (2-4): more voices sound wider and denser.
- Delay (20-80 ms): shorter values stay tighter; longer values become spacious.
- Depth (1-8 ms): higher values make the pitch movement more obvious.
- Rate (0.1-5 Hz): low rates drift slowly; high rates shimmer or wobble.
- Voice level (0.1-0.9): higher values make the effect wetter and louder.
Limits and edge cases
- Input files are capped at 10 MiB.
- Embedded album art or video streams are dropped from the output.
- The dry gain and output gain are fixed to avoid clipping; use the voice-level control for effect amount.
- ffmpeg's chorus filter has no feedback or separate dry/wet mix knob, so those are listed as out of scope.
- Output is re-encoded; choose wav or flac when you need a lossless output container.
FAQ
What is the difference between voices and decay?
Voices controls how many delayed copies are mixed in. Decay controls the level of each copy. More voices make the sound wider; more decay makes those voices louder and more obvious.
Why do the voices not all use the same delay and rate?
Each added voice is staggered by 8 ms and modulates at a slightly different rate. That deterministic spread prevents copies from lining up perfectly and collapsing back into one thin-sounding delay.
Can I use this on vocals and guitars?
Yes. Subtle two-voice settings work well for vocals and clean guitars. Pads, synths, and ambient textures can tolerate more voices, depth, and decay.
Does this upload my audio?
No. The page runs the ffmpeg WebAssembly runtime in your browser tab. Your audio stays local to the browser while the effect is rendered.
Developer & Automation Access
Run it from the terminal
Same engine as this page, headless — via the gizza CLI:
gizza tool chorus 'url=https://example.com/input' 'voices=2' 'delay_ms=50' 'depth_ms=2' 'speed_hz=0.4' 'decay=0.4' 'format=mp3'New to the CLI? Get gizza →
Open it by URL
Pre-fill and auto-run this tool with query parameters — the names match the API/CLI:
https://gizza.ai/tools/chorus/?url=https://example.com/input&voices=2&delay_ms=50&depth_ms=2&speed_hz=0.4&decay=0.4&format=mp3Machine-readable descriptor: tool.json — title + parameters JSON Schema for agents.