Online MP3 Compressor
Reduce MP3 file size without significant quality loss
Need to shrink an MP3 file for email, messaging, or storage? Our free MP3 compressor re-encodes your file at a lower bitrate to reduce its size. Choose from quality presets or set a custom bitrate. Processing happens in your browser — files are never uploaded to any server.
What You Can Do
- Reduce MP3 size by 50–90% depending on quality settings
- Choose from 6 quality presets: Maximum (320 kbps] to Minimum (64 kbps]
- See estimated file size before compressing
- Detect source bitrate automatically
- Process entirely in your browser — files stay private
- Download compressed file instantly
How to Compress an MP3 File
- Upload your MP3 file (drag and drop or click to browse]
- Choose a compression level or set a custom bitrate
- Review the estimated file size and reduction percentage
- Click "Compress" and download the smaller file
Frequently Asked Questions
Does compression reduce audio quality?
Yes, reducing bitrate means some audio detail is lost. At 128 kbps most listeners cannot tell the difference from the original. Below 96 kbps quality loss becomes more noticeable, especially for music.
What is the best bitrate for MP3?
128 kbps offers a good balance of quality and file size for most purposes. 192–256 kbps is near-transparent quality. 320 kbps is the maximum for MP3.
Can I compress a file that is already at a low bitrate?
You can, but re-encoding an already compressed file will further degrade quality without significant size reduction.
Are my files uploaded to a server?
No. Processing happens entirely in your browser using WebAssembly technology. Your files never leave your device. A server fallback is available if your browser does not support WebAssembly.
What is the maximum file size?
Up to 50 MB. This covers most MP3 files — a typical 5-minute song at 320 kbps is about 10 MB.
Why Use Our MP3 Compressor
No software to install, no account needed. Compress any MP3 file in seconds with real-time size estimation. Perfect for reducing file size before sharing via email, messaging apps, or uploading to websites with size limits. Privacy-first: all processing happens in your browser.
