AAC to MP4
Convert an AAC audio file to MP4 without losing quality — the audio is repackaged, not re-encoded. Runs entirely in your browser; nothing is uploaded.
Input
Lossless: the AAC audio is copied into a new MP4 container without re-encoding, so quality is identical.
MP4 audio
Upload an AAC file and press Convert to MP4. Everything runs in your browser — the file is never uploaded.
Also available with
Guides
What AAC to MP4 does
A raw .aac file is a bare stream of audio frames with no container, so many players, editors and upload forms refuse it. This tool repackages the same audio into a standard MP4 file. Nothing is decoded or re-encoded, so the sound is identical to the original — only the wrapper changes.
How to use it
- Upload an AAC file.
- Click Convert to MP4.
- Preview the result, then download it.
Good to know
The tool expects raw AAC in ADTS format, which is what a plain .aac file is. Files that are already .m4a or .mp4 are already in a container and don't need converting. The output is audio-only.
Privacy
The file is processed on your device. Nothing is sent to a server.