Compress audio
Make an audio file small enough to send, without making speech hard to follow.
Size in audio is bitrate multiplied by time, and for speech most of that bitrate is being spent on nothing. A lecture recorded as a 100 MB WAV is perfectly intelligible at 32 kbps mono, which is around a fortieth of the size. Music is a different matter and deserves a higher setting, which is why this asks rather than assuming.
How to use it
- Add the audio file.
- Pick a bitrate, and choose mono if it is speech.
- Press Compress audio and download the result.
Why use this tool
Completely private
Everything runs inside your browser. Your files and text are never sent to a server.
Free, with no limits
No sign-up, no watermarks and no cap on how many times you can use it.
Instant results
There is no upload or queue to wait for, so results appear as fast as your device can work.
Works on any device
Runs in any modern browser on phone, tablet or desktop. Nothing to install.
Frequently asked questions
- What bitrate should I use?
- For speech, 64 kbps mono is comfortable and 32 kbps is still perfectly clear. For music, 128 kbps is the point below which most people start to notice, and 192 kbps is close to transparent.
- What does mono actually do?
- It merges the left and right channels into one, which halves the data again. A voice recording has no stereo information worth keeping, so this is usually the single biggest saving available.
- Can I get quality back later?
- No. Compression like this discards information permanently, and converting the small file back to a large one only makes it big again. Keep the original if you might need it.
- Why does my file sound muffled at the lowest setting?
- Because below about 64 kbps there are not enough bits for the full range, so the top end is dropped first. That suits speech, where the important sound is low down, and it is why the very low settings also reduce the sample rate.