Compress MP3 Online
Lower the bitrate of MP3 files to make them smaller. Free, fast and private.
Processed in your browser and never uploaded. Works best with files up to about 500 MB.
Files are processed on your device and never leave it.
No upload wait, results appear right in your browser.
No sign up, no watermark and no limits.
How to use Compress MP3
Re-encoding an MP3 at a lower bitrate makes it smaller. 96 to 128 kbps is a good balance for most listening.
- Choose a bitrate, or a target size, and mono for voice recordings.
- Click the box or drop your audio files.
- Wait while the audio is encoded to MP3 on your device.
- Download the compressed MP3.
Frequently Asked Questions
Is this Compress MP3 free?
Yes. Compress MP3 is completely free, with no sign up, no watermark and no daily limit.
Are my files uploaded to a server?
No. Everything runs inside your browser on your own device, so your files are never uploaded, stored or seen by anyone.
Why does it take longer than image compression?
Video and audio are re-encoded on your own device. Speed depends on your processor and the length of the file, so long videos can take several minutes.
Does it work on mobile?
Yes. It works in Chrome, Safari, Edge and Firefox on Android, iPhone, Windows and Mac.