Convert AAC to M4A
Runs locally in your browser via a WebAssembly build of ffmpeg. Your file is never sent to a server.
- Choose a .aac 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.
AAC vs M4A
AAC is a compressed audio format used by Apple devices and YouTube; quality depends on the encoder and bitrate. M4A is Apple's default audio container, produced by Voice Memos, GarageBand and podcast exports.
Frequently asked
Why convert AAC to M4A?
AAC is a compressed audio format used by Apple devices and YouTube; quality depends on the encoder and bitrate. 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