Audio Compressor (Dynamics)
Reduce the gap between the loudest and quietest moments so speech and music sit evenly.
MP3, WAV, M4A, FLAC, OGG, Opus, AIFF, WMA, AMR and the sound of most videos. Files stay on your device.
How it works
- Choose an audio file.
- Pick a preset, or set threshold, ratio, attack, release and makeup gain.
- Preview and watch the gain reduction.
- Export and download.
What a compressor does
A compressor turns down the parts of a signal that rise above a threshold. The ratio says how strongly: at 4:1, every 4 dB over the threshold becomes 1 dB. With the loud parts reduced, the whole file can be turned up, so quiet details become easier to hear without the loud parts getting louder.
The curve on the page is the static transfer curve of your settings: input level on the bottom, output level on the left.
The controls
- Threshold: the level above which compression starts.
- Ratio: how much the signal above the threshold is reduced.
- Attack and release: how fast the compressor reacts, and how fast it lets go. Slow attacks let drum hits through; fast ones control peaks.
- Knee: a soft knee eases into compression gradually instead of switching on at the threshold.
- Makeup gain: lifts the compressed signal back up. Automatic makeup brings a full-scale input back to full scale.
Presets and honest limits
The presets (Gentle, Vocal, Podcast, Broadcast, Drum bus) are starting points, not magic: the right threshold depends on how loud your recording is. Use Preview and the before and after table, which shows the peak, average level and the crest factor (peak to average) of the exported file; a lower crest factor means less dynamic range.
Heavy compression also raises background noise and breaths. A compressor does not remove clipping or noise that is already in the recording.
Questions
What settings are good for a voice recording?
Start with the Vocal or Podcast preset, then lower the threshold until the loud words are reduced by 3 to 6 dB. Check the preview for pumping or breathing noises.
What is the difference between a compressor and a limiter?
A limiter is a compressor with a very high ratio and fast reaction, used to stop peaks at a ceiling. A compressor shapes dynamics more gently.
What does auto makeup gain do?
It adds the gain that would bring a full-scale input back to full scale after compression. It is a convenience, not a loudness match: check the result and adjust.
Does it work on stereo files?
Yes. By default both channels share the same gain so the stereo image does not shift. Unlink them under Advanced if you want independent control.