Audio
Convert MP4 to MP3 Online — Free
Pull the audio out of any MP4 video and save it as an MP3. ReFile uses FFmpeg under the hood, so the conversion is lossless from the source stream — no re-encoding artifacts beyond what's already in the file.
- No signup to try
- Sandboxed processing
- Files deleted in 24 h
What this does
- Extract MP3 at any bitrate (say 'as 320kbps MP3' or '128kbps for podcasts')
- Mono or stereo — say 'mix down to mono' for voice recordings
- Trim while you're at it — 'just the first 30 seconds as MP3'
How it works
- 1
Upload your MP4
Drop it above, or click to pick from your device. We validate the format immediately — no spinning on a file we can't process.
- 2
Run the conversion
The recipe runs in an isolated cloud sandbox — same as every other ReFile job. No AI guessing involved; it's a hand-written command that does one thing.
- 3
Download the MP3
Result lands in seconds. Files auto-delete from our servers after 24 hours; signed download URLs expire in the same window.
Frequently asked
- Is the audio quality the same as the original?
- Yes — ReFile copies the audio stream when it can, and only re-encodes if you specifically ask for a different bitrate. Either way the output is a standard MP3 playable in any player.
- How long does it take?
- A 10-minute MP4 typically converts to MP3 in under 5 seconds. Larger files (1+ hour videos) take longer because the file has to be uploaded first.
- Do you keep my file?
- Inputs and outputs are deleted automatically 24 hours after upload. See /security for the full data flow.