Free Online Compressor
Even out loud and quiet parts.
Drag & drop your audio file here
or
Max file size: 100 MB · MP3, WAV, FLAC, OGG
Original
beats per minute
musical key
Level where compression kicks in. Lower thresholds compress more of the signal.
How hard the compressor squeezes. 2:1 is gentle glue; 10:1 and up is heavy limiting.
How fast compression reacts. Fast attack tames transients; slow attack lets punch through.
How fast compression lets go. Too fast can sound pumpy; too slow can dull the sound.
Processing…
Result
How it works
A compressor is the most-used dynamics tool in music production: it automatically reduces the volume of loud passages so the quiet parts can be heard clearly, making recordings sound consistent, polished and professional. Podcasts use it to even out speakers; music uses it on everything from vocals to full mixes.
This tool drives the browser's native DynamicsCompressorNode with the four classic controls: threshold (where compression starts), ratio (how hard it squeezes), attack (reaction speed) and release (recovery speed), plus a fixed 20 dB knee for a smooth onset. The three presets - Vocals, Drums and Glue - cover the most common starting points.
It is a real-time effect, so you hear every slider move instantly while previewing. Like every tool here it is 100% client-side: your audio is processed in your own browser tab, never leaves your device, and nothing is uploaded anywhere.
Frequently asked questions
What does a compressor actually do?
It automatically turns down the loud parts. Anything above the threshold gets reduced by the ratio - at 4:1, a signal 4 dB over the threshold comes out only 1 dB over. The result is a more even, consistent, "produced" sound.
Which preset should I start with?
Vocals for voice recordings and podcasts, Drums for punchy percussion loops, Glue for full mixes that need subtle cohesion. Each preset is a starting point - nudge the sliders while previewing.
What do attack and release do?
Attack is how fast the compressor clamps down (fast = tames sharp transients like snare hits; slow = lets punch through). Release is how fast it lets go (too fast sounds pumpy, too slow sounds dull and lifeless).
Is there a file size limit? Is it private?
Files up to 100MB are supported. Compression runs on a real-time Web Audio graph in your browser - your audio never leaves your device.