How to use it
- Open your file and tick "Compressor".
- Lower the threshold until the loudest words sit above it, typically −20 to −30 dB for voice.
- Set the ratio: 2:1 to 4:1 for natural speech, 6:1 and up for an aggressive, broadcast sound.
- Add make-up gain to bring the level back up, enable the limiter, audition live, then apply and download.
The four controls
Threshold is the level where compression starts. Ratio is how hard it pushes: at 4:1, a signal that goes 8 dB over the threshold comes out only 2 dB over. Attack is how fast it reacts (fast attack tames sharp consonants but can dull them), and release is how quickly it lets go after the loud part ends.
Because compression lowers the peaks, the output is quieter. Make-up gain adds that level back uniformly, so the quiet words end up louder than before.
See what a compressor does
The line shows output level for every input level. Above the threshold, the line bends flatter: that is the ratio. The bars below are the peaks of nine spoken words, before (outline) and after (filled).
Loud-to-quiet spread: 28 dB → 17.5 dB
A word 8 dB over the threshold comes out 2.0 dB over. With make-up gain, the quietest word is now 0.0 dB louder than it was.
Questions
Is my audio uploaded anywhere?
No. The file is decoded, processed and encoded by your own browser using the Web Audio API. Nothing is sent to a server, which is also why it works on large files without a queue.
Does this compress the file size?
No. Dynamic range compression changes volume, not file size. To make a smaller file, export MP3 or OGG at a lower bitrate in the converter.
What settings should I use for a podcast?
Threshold around −22 dB, ratio 3:1, attack 5–10 ms, release 150–250 ms, then make-up gain until peaks sit near −3 dB, with the limiter on.