M4A to MP4
Rewraps your M4A's AAC into an MP4 container with no re-compression, so the quality is untouched.
Drop an M4A file here
Everything happens on your device — your files are never uploaded.
file.m4a
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Converting…
Done
How it works
- 1 Drop your M4A file, or pick it from your device.
- 2 Click Convert to MP4 and watch the progress bar as it rewraps the audio.
- 3 Download your MP4. It never leaves your browser.
Built with open source
- Mediabunny — Converts and edits video and audio in the browser via WebCodecs. Add-on encoders cover MP3, AAC, and FLAC. · MPL-2.0
Frequently asked
Does the MP4 contain video? +
No. You get an audio-only MP4: a standard MP4 container with one AAC audio track and no video. It's for players and apps that demand a .mp4 extension.
Is my M4A uploaded anywhere? +
No. The whole conversion runs in your browser with WebCodecs. The audio never leaves your device.
Will the audio quality change? +
M4A and the MP4 both use AAC, so the audio is re-encoded as AAC at a standard high-quality bitrate. Chrome and Edge do this natively. On Firefox and Safari a small encoder loads automatically.