Compress MP3: how it works
Audio size depends mostly on bitrate. A 320 kbps MP3 uses about 2.4 MB per minute; at 96 kbps it's about 0.7 MB. For speech, 64 kbps mono is clear and tiny.
How to compress MP3 and audio files
- Add audio files.
- Pick a bitrate (96 kbps for music on the go, 64 kbps mono for voice).
- Download the smaller files.
Features
- Choose bitrate320 down to 64 kbps.
- Mono optionHalves the size of voice recordings.
- BatchWhole folders.
- PrivateNo upload.
Frequently asked questions
Will compressing again lose quality?
Yes, each MP3 encode loses a little. Compress from the best copy you have.
Is the Compress MP3 free?
Yes. The Compress MP3 is completely free with no sign-up, no watermarks, no daily limits and no premium tier.
Are my files uploaded to a server?
No. FileStripe processes your files locally in your web browser using JavaScript. Nothing is uploaded, so the Compress MP3 is safe for private photos and confidential documents and even works offline once the page has loaded.
Does it work on iPhone and Android?
Yes. The Compress MP3 works in Safari, Chrome, Firefox, Edge and Samsung Internet on phones, tablets and computers. On a phone you can pick files from your photo library or files app and share the result straight to another app.
Last updated · Processing happens locally in your browser.