AAC to MP4 Converter

Need your AAC audio in an .mp4 file? This free converter wraps .aac and .m4a audio into an audio-only MP4 in seconds — right in your browser, no software or signup. Files up to 30MB are converted directly and nothing is stored after your download.

How to convert AAC to MP4

1. Upload your AAC or M4A file

Drag a file onto the box above, or click to browse. Both .aac and .m4a are accepted.

2. Choose a bitrate

MP4 is already selected as the output. Pick a bitrate — 320 kbps for best quality, or lower for smaller files.

3. Convert & download

Click Convert & Download. Your MP4 audio file downloads automatically.

AAC, MP4, and M4A

An MP4 audio file holds AAC audio inside the MPEG-4 container — the same codec you started with. .m4a is really just an MP4 container renamed for audio, so an .mp4 audio file and an .m4a file are near-identical; some video tools simply prefer the .mp4 extension. See AAC vs M4A for the codec-vs-container explainer.

When to use MP4 audio

Choose MP4 when a video editor, player, or platform expects a .mp4 file, or when you're assembling audio for a video project. For a pure audio file on Apple devices, AAC to M4A is the more conventional target.

Frequently Asked Questions

How do I convert AAC to MP4?

Upload your .aac or .m4a file, keep MP4 selected and pick a bitrate, then click Convert & Download. The MP4 file is created and downloaded automatically.

Is an MP4 audio file the same as M4A?

Nearly. Both hold AAC audio in an MPEG-4 container; .m4a is just the audio-specific extension. Some video tools prefer the .mp4 extension.

Does this add video to the file?

No. The output is an audio-only MP4 — it contains your AAC audio in an MP4 container, with no video track.

Is the AAC to MP4 converter free?

Yes — it's completely free, with no account, no watermarks, and no limit on how many files you convert.