Convert AAC to M4A

Upload an AAC file and convert it to M4A — all in your browser.

A lossless repackaging, not a re-encode

This is one of the few audio conversions with no quality cost at all. AAC audio is equally at home in a raw ADTS stream and an MP4 container, so the tool copies your audio bit-for-bit into the M4A wrapper. No decoding, no re-encoding, and it finishes almost instantly even for long files.

Why bother wrapping AAC in M4A

Raw .aac files are second-class citizens: no tags, no cover art, no chapter support, and patchy app compatibility. The same audio as M4A plays natively on iPhone and Android, accepts full metadata, and imports cleanly into music libraries.

If you captured AAC audio from a stream or recorder, this is almost always the format it should live in.

Frequently asked questions

Is the audio really untouched?

Yes. Because AAC fits the MP4 container natively, the stream is copied as-is. The output sounds identical because it is the identical data.

Why is this conversion so fast?

No re-encoding happens. Copying packets into a new container is mostly I/O work, so even hour-long files finish in seconds.

Can I add album art afterwards?

Yes. Once the audio is in M4A, the metadata tools can embed cover art and edit tags.