Tools / File Converter / M4A to AU Converter

M4A to AU Converter

Convert M4A files to AU. Free, without uploading.

This tool converts M4A files to AU. M4A is Apple’s format for AAC audio. iPhone voice memos and iTunes use it; it is smaller than MP3 at the same quality.

Sun/NeXT audio. AU is lossless, so the audio keeps the quality it has in the M4A file.

Conversion runs on your device; your file is never sent to a server. The components download once on first use, and later conversions start right away.

How to use

1. Choose the M4A file, drag it in, or paste its link.
2. Choose the audio quality; optionally enter a start and end time.
3. Press "Convert" and download the AU file.

Frequently asked questions

Will audio quality drop when converting to AU?

No. AU is lossless.

Is there a file size limit?

No fixed limit; your device’s memory decides. Computers usually handle files up to 1–2 GB.

Is my file uploaded?

No. Your M4A file is converted to AU inside your browser.