Is MP4 to M4A lossless?

Usually. When the MP4's audio is AAC, the track is copied into M4A unchanged. Other codecs are re-encoded.

What's the difference between MP4 and M4A?

They are the same container. M4A signals that the file holds only audio, so music apps treat it as a song rather than a video.

MP4 to M4A

Save the sound from an MP4 video as an M4A audio file. Processing stays on your device.

Files stay on your device

Drop a file to convert

See its format, then choose an output.

Any media file this browser’s engine can read.

How to convert MP4 to M4A online

Open an MP4 and export just its audio as M4A, the format Apple Music, iTunes, and most phones play natively. Most MP4s already carry AAC audio, which the converter copies into M4A without re-encoding.

Step 1
Choose your MP4
Pick a file or drop it into the converter above.
Step 2
Keep M4A
M4A is selected; choose another audio format if you need one.
Step 3
Download the M4A
Save the audio when the conversion finishes.

What to expect

Supported inputs: MP4 videos and other readable video or audio files.
What happens: The video track is dropped. AAC audio is copied into M4A when possible, keeping its original quality; other audio is re-encoded.
Limits: The MP4 needs an audio track. Re-encoding to AAC depends on this browser's encoder support.

Private by design

Your video stays on your device

Mastershot processes your file locally in this browser. It does not need to be uploaded to a server, and you do not need an account to use the tool.

No upload
No signup
No watermark