Convert MP4 to M4A
Runs locally in your browser via a WebAssembly build of ffmpeg. Your file is never sent to a server.
- Choose a .mp4 file from your device.
- Click convert to M4A.
- Download the result.
Maximum file size: 100 MB. The first conversion loads a ~30 MB converter engine, once per visit. Nothing is uploaded - conversion runs on your device.
MP4 vs M4A
MP4 is a widely supported video container; acceptance also depends on the video and audio codecs inside it. M4A is Apple's default audio container, produced by Voice Memos, GarageBand and podcast exports.
Frequently asked
Why convert MP4 to M4A?
MP4 is a widely supported video container; acceptance also depends on the video and audio codecs inside it. M4A is Apple's default audio container, produced by Voice Memos, GarageBand and podcast exports. Converting between them is common when a file made for one use needs to work for the other.
Does this upload my file anywhere?
No. Conversion runs entirely on your device using a WebAssembly build of ffmpeg - the file never reaches a server.
Is there a file size limit?
Yes, 100 MB per file, to keep conversion reliable inside the browser.
Koldflux exports every clip in the right format automatically - no manual conversion step.
Automate this in Koldflux