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.

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How it works

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.

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.

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.