# Compress an audio file

> Re-encode an audio file as MP3 at a lower bitrate to cut file size, with a single bitrate slider.

Open the tool: https://yourbrowsercandoit.com/compress-audio

Lower the bitrate of an audio file. Free, no signup. Runs entirely in your browser; files are never uploaded.

## How it works

Drop any audio file (MP3, WAV, M4A, OGG, FLAC). Set a target bitrate from 64 kbps (smallest, fine for voice) to 320 kbps (max MP3 quality). The tool runs the file through ffmpeg.wasm with libmp3lame, locally in your browser. For a 1-hour 320 kbps MP3, dropping to 128 kbps cuts the file from ~140 MB to ~55 MB with no audible difference for most listeners. For voice-only content (podcasts, lectures), 64-96 kbps is often enough. The progress bar tracks encoding. Output filename has -compressed.mp3 appended. For FLAC or WAV inputs, the size drop is dramatic since you're moving from lossless to lossy.

## How to use it

1. **Drop your audio file.** Lossless inputs like WAV and FLAC see the biggest size drops.
2. **Pick a bitrate.** 128 kbps for music, 64-96 kbps for voice recordings and podcasts.
3. **Compress.** ffmpeg.wasm re-encodes the file locally with libmp3lame; a progress bar tracks it.
4. **Download.** The -compressed.mp3 downloads, often half the size or smaller.

## Frequently asked questions

### What bitrate should I pick?

128 kbps is standard for music. 96 kbps for voice. 192 kbps if you have audiophile listeners. Going below 64 kbps starts to sound rough on music.

### Can I compress without losing quality?

Not really. MP3 is lossy, going lower always loses something. For lossless compression, FLAC is the format, but the tool doesn't output FLAC.

### How much smaller will my file get?

Depends on the source bitrate. Going from 320 to 128 kbps cuts file size roughly in half.

### Is my audio uploaded?

No. ffmpeg.wasm runs in your browser, the file never leaves your device.

## Related tools

- [Video to MP3](https://yourbrowsercandoit.com/mp4-to-mp3): Extract audio from any video as MP3.
- [Trim audio](https://yourbrowsercandoit.com/trim-audio): Cut an audio file to a start/end time.
- [Trim video](https://yourbrowsercandoit.com/trim-video): Cut a video on a filmstrip timeline, to the exact frame.
- [Video to GIF](https://yourbrowsercandoit.com/video-to-gif): Turn a clip into a GIF or WebP, with a live preview and size estimate.
- [Compress video](https://yourbrowsercandoit.com/compress-video): Lower the bitrate or resolution.