MP3 Compressor
Re-encode MP3 at a lower bitrate for a smaller download.
Drop a MP3 file to compress
Output: MP3 · re-encoded in your browser
No server upload — processed on your device
Computer · URL · cloud · drag & drop
How to use this tool
Add a MP3 file
This page accepts MP3. Max 100 MB — processing stays in your browser.
Tune compression
Lower the bitrate bias for a smaller MP3. Prefer masters (WAV/FLAC) when you still have them.
Download MP3
Save the compressed MP3 locally when you are happy with the size.
Frequently Asked Questions
More on quality loss: conversion quality guides · compression guides
Is the mp3 compressor free?
Yes. Format Convertly compresses files in your browser with no signup.
Do you upload my files?
No. Encoding stays on your device.
What does MP3 Compressor output?
Output is MP3.
Need a different format?
Open the MP3 format hub for converters, comparisons, and related tools.
Does compressing audio reduce quality?
Lossy MP3 output discards some detail by design. Prefer WAV/FLAC masters and compress once for sharing.
Does WAV to MP3 lose quality?
Yes technically. At sensible bitrates most listeners are fine — archive the WAV/FLAC original.
How does audio compression work?
Delivery compressors re-encode to a smaller MP3 at a bitrate bias. See How audio compression works and How bitrate affects file size.
Should I compress from WAV or from MP3?
Prefer WAV/FLAC masters. Re-encoding MP3→MP3 stacks loss — covered under Lossy vs lossless compression.
Where can I learn more about compression?
Browse Format Convertly’s Compression guides — what compression is, lossy vs lossless, image/video/audio how-tos, bitrate, and PDF size tips — each links back to the matching compressor.
Ready to convert more formats?
Browse converters or jump back to the tool above.