MP3 Compressor
Shrink MP3s for email, messaging apps or limited storage.
- Files never leave your device
- 100% free
- No sign-up
- No watermark
- Works offline after first load
How to compress an MP3
- Open your MP3 files.
- Choose a bitrate, mono or a target size.
- Click Compress and download.
About MP3 Compressor
New tool.
Good for
- New tool
Frequently asked questions
How much smaller can my MP3 get?
A 320 kbps song at 128 kbps is 60% smaller and still sounds good; speech at 64 kbps mono is over 80% smaller.
Can I compress to a specific size?
Yes — type the size in MB under Target file size and the bitrate is calculated from the length (for example for email or WhatsApp limits).
How can I get even smaller files?
Choose M4A (AAC) or Opus: they sound better than MP3 at low bitrates — Opus at 32–48 kbps is excellent for speech.
Can I convert many files at once?
Yes. Add as many files as you like; they are converted one after another with the same settings, each with its own download, plus a ZIP of all of them.
Are my files uploaded?
No. Files are compressed in your browser, so your audio never leaves your device. Some formats use FFmpeg (WebAssembly), which downloads once — about 32 MB — and is then cached.