Audio tool

Convert MP3 Files to AU on Your Device

Convert MP3 to AU in your browser for legacy workstation exchange. The source remains on your device throughout local processing.

Route MP3 → AU

or drop here · up to 500 MB

Max 50 MB per file

Preview (optional)

When your browser supports it, your audio plays here. You can still convert your file if preview does not load.

Ready

Use upload name

The device processor performs decoding and encoding during the job during this MP3-to-AU job.
Large MP3 inputs may take several minutes on older hardware.
Compare the AU duration with the source before publishing.

AU serves Unix workstations and older audio software, whereas MP3 commonly serves phones, websites, podcasts, and universal playback.
For MP3-to-AU delivery, plan for limited modern consumer support.
After leaving MP3, the receiving app must support the streams encoded inside AU, not only its extension.

MP3 to AU taking too long? Try a small source first to separate a performance issue from a format issue.
AU converted from MP3 not opening? Test a compatible player and inspect the output streams.
If AU is rejected, compare its codec and stream settings with the destination specification.

When does MP3 to AU conversion make sense?

It is useful when MP3 media created for easy sharing must enter a AU system designed for legacy workstation exchange.

Where is the MP3 source processed?

The browser prepares AU from MP3 on this device instead of sending the source to a remote conversion server.

How can I approve AU converted from MP3?

Test the AU file in the receiving app and compare duration, channels and loudness with the MP3 source.

Quick use cases