Audio Compressor — Reduce MP3, WAV & FLAC Size Free Online, No Upload
Reduce audio file size with bitrate presets — private, free, powered by FFmpeg.
Your computer does 100% of the processing — not a server, not the cloud.
FFmpeg runs directly inside your browser via WebAssembly. Your audio files never leave your device.
- ✓Files stay on your computer — zero upload, zero cloud
- ✓Works offline once the engine has loaded
- ⚠First use downloads ~32 MB FFmpeg engine — cached after that
Drop an audio file here or browse files
MP3 · WAV · AAC · FLAC · OGG · OPUS and more
About the Audio Compressor
Audio compression works by re-encoding the file at a lower bitrate. This tool uses FFmpeg running in your browser via WebAssembly. Your files never leave your device.
Related: Audio Clipper to trim files before compressing, or Audio Converter to change format.
Frequently Asked Questions
Is the Audio Compressor free?
Yes — completely free. No account, no subscription, and no file size limit.
Are my audio files uploaded to a server?
No. FFmpeg runs locally in your browser via WebAssembly. Your audio files never leave your device.
Do I need an account?
No account, no login, and no signup required.
What audio formats are supported?
Input: MP3, WAV, FLAC, AAC, OGG, M4A. Output format depends on the preset — typically MP3 or AAC for lossy compression, or a lower-bitrate version of the original format.
What bitrate should I choose?
For music, 128 kbps is the minimum for acceptable quality on typical speakers and headphones. 192 kbps is the sweet spot for quality and file size. For voice recordings and podcasts, 64–96 kbps is sufficient.
Can I re-compress an already-compressed MP3?
You can, but each re-encoding pass adds generation loss — artifacts from the first pass get encoded again. Start from the highest-quality source you have, ideally FLAC or WAV.