Practical starting preset
The editor opens at −18 dB threshold, 4:1 ratio, 10 ms attack, 250 ms release, and a 12 dB knee.
Audio compressor online
for controlled dynamics
Reduce peaks above a chosen threshold with adjustable ratio, attack, release, and knee, then compare and export locally in your browser.
Real dynamics processingAdjustable timingLocal A/B preview
You can also drag and drop an audio or video file anywhere on this page.•Compatibility depends on the file codecs and device: MP3, WAV, M4A, AAC, FLAC, OGG, WebM, MP4, MOV, MKV, and more
Dynamic-range compression, not file-size compression
This tool uses the browser's DynamicsCompressorNode to turn down signal portions that cross the threshold. Ratio controls how strongly those portions are reduced, while attack, release, and knee shape how the gain reduction begins and recovers.
Preview equals export
The same compressor settings feed real-time playback and offline WAV or compressed export.
A/B comparison
Bypass the compressor without losing the current settings, then switch back to judge the dynamics change.
How to set an audio compressor
Begin with a representative passage and change one parameter at a time. Compression is easier to judge when the preview includes both ordinary and loud moments.
- 1
Choose a representative section
Play a passage containing normal level and the peaks you want to control. Start with the practical preset rather than extreme settings.
- 2
Set amount before timing
Adjust threshold and ratio to decide how much is reduced, then refine attack, release, and knee for the way compression enters and recovers.
- 3
Use A/B and export deliberately
Bypass the effect to compare dynamics, not just loudness. This tool has no automatic makeup gain, so adjust the final level separately when needed.
What the compressor does not promise
- Dynamics compression does not reduce the file size; use the bitrate converter for that task.
- The tool does not measure or normalize integrated loudness in LUFS.
- Compression can make transients dull or increase audible noise when settings are too aggressive.
- There is no automatic makeup gain, limiter, side-chain input, or multiband processing.
Useful starting points for speech and music
- Control occasional voice peaks before manually adjusting the final level.
- Tighten the dynamic range of a rough podcast or narration preview.
- Soften strong musical transients with a moderate ratio while comparing against the original.
Compressor controls in practical terms
These controls interact. Moderate changes make it easier to hear which parameter solved the original problem.
ParameterWhat it controlsTypical audible result
Threshold and ratio
Where compression starts and how strongly signal above that point is reduced.
Lower thresholds and higher ratios produce more gain reduction.
Attack
How quickly gain reduction responds after the signal crosses the threshold.
A fast attack controls transients more firmly; a slower one lets more initial impact pass.
Release and knee
How quickly reduction recovers and how gradually compression begins around the threshold.
Release that is too short may pump; a softer knee usually makes entry more gradual.
Dynamics processing stays local
The decoded samples are compressed, previewed, and rendered in browser memory. The application server does not receive the selected audio for this effect. Site resources and consented analytics may still make network requests.
Audio-compressor questions
Distinguish dynamics control from normalization, limiting, and file-size compression.
Does an audio compressor make the file smaller?
No. It reduces dynamic range inside the sound. To reduce MP3 storage size, use a bitrate converter.
Does compression automatically make audio louder?
Not in this tool. Compression turns down portions above the threshold and there is no automatic makeup gain. Final level can be adjusted separately.
What causes pumping or breathing?
Very strong gain reduction or an unsuitable release can make the background level rise and fall audibly. Use a milder ratio, a different threshold, or a longer release.
Should I normalize before or after compression?
It depends on the goal. Compression usually shapes dynamics first; a later peak or loudness step can then set the delivery level. Always leave enough headroom between stages.