Compress an MP3 file
Audio too big to email, upload or send in a messenger? Lower the bitrate and, for speech, switch to mono — a podcast or voice note often shrinks to a third of its size without sounding any different.
Your files never leave your browser
How to use
- 1
Pick a bitrate: 64–96 kbps for speech, 128–160 kbps for music.
- 2
Turn on mono for voice recordings — it halves the size again.
- 3
Drop your audio files and download the smaller MP3s.
FAQ
How much smaller will the file be?
It depends on the original. A 320 kbps song at 128 kbps is 60% smaller; a stereo voice memo at 64 kbps mono can shrink by 80% or more.
Will I hear a difference?
For speech at 64–96 kbps, almost never. For music, 128 kbps is fine on phone speakers and earbuds; go to 160 kbps if it is for careful listening.
What does mono do?
It folds the two stereo channels into one. Speech loses nothing because voice is recorded in the middle anyway; music loses its stereo width.
Is the audio uploaded?
No. FFmpeg runs in your browser as WebAssembly; files never leave your device.
Which formats can I compress?
MP3, WAV, M4A, OGG and FLAC. The result is always MP3, which plays everywhere.