AnyFormat

00 MP4 → M4A

MP4 to M4A

The same AAC audio, just without the video.

Drop files or a folder here

or choose from your device · paste with ⌘V / Ctrl+V

.mp4 .m4v

03Options 5

Right for speech, wrong for music. At a fixed quality the file size does not change — but mono tolerates a much lower quality than stereo, so combine the two to actually shrink the file.

Leave at 0 for the whole file.

0 means run to the end.

  • No upload The conversion runs in this tab. Your file never travels — not to us, and not to the advertising.
  • No sign-up, no email, no daily cap There is no account system to sign up to.
  • No size limit we invented Only your device's memory — about ~2 GB on a desktop browser, ~400 MB on a phone.
  • Turn your Wi-Fi off and convert anyway The conversion needs nothing but this page. Ads will not load without a connection; your file will still convert. That is the whole claim, and it takes five seconds to check.

Takes the audio out of an MP4 and puts it in an M4A. Both use the same container family and MP4 audio is already AAC — so this is the cleanest possible way to get audio out of a video.

Why this beats converting to MP3

An MP4's audio track is AAC, and an M4A is AAC in an MP4 container. So this conversion changes the wrapper and keeps the codec — no second lossy generation, no quality question at all.

Converting the same file to MP3 means decoding the AAC and re-encoding into a less efficient codec. If the target accepts M4A, this is strictly the better choice: identical audio, smaller file, no loss.

What M4A will not play on

Older car stereos, some gym equipment, a few hardware players, and any system that specifically demands .mp3 uploads. Everything else made in the last fifteen years takes it.

This copies the audio rather than re-encoding it

The audio inside an MP4 is almost always already AAC, and M4A is the same AAC in a container that names itself as audio. So the stream is lifted out and rewritten, not decoded and re-compressed: the result is bit-identical to the audio that was in the video, it happens in a fraction of the time an encode would take, and there is no generation loss to argue about. Converting the same file to MP3 instead means decoding AAC and re-encoding to a different lossy codec, which does lose quality, for a file that is usually larger.

Other names for this

Also searched as “mp4 to aac”, “extract m4a from mp4”.

Questions

Is any quality lost?
Effectively none. The audio is AAC in both, so it is a container change rather than a re-encode.
Should I use this or MP4 to MP3?
This one, if the target accepts M4A — it is smaller and loses nothing. MP3 only when something specifically requires it.
Is my file uploaded?
No. The demuxing, decoding and encoding all happen in this tab using the browser’s own media stack plus a WebAssembly encoder. A recording can be an interview, a lecture, a private call — none of it is transmitted. Turn your Wi-Fi off after the page loads and it still works.
How large a file can I convert?
There is no imposed limit, only your device’s memory — around 2 GB in a desktop browser and 400 MB on a phone, since the file is held in memory while it converts. A two-hour video converts in well under a minute on a laptop.
Can I convert several files at once?
Yes. Drop as many as you like, or a whole folder. Each keeps its original name with the new extension, and you can download them individually or as a ZIP.