AU Converter
Convert AU audio files to MP3, WAV, OGG, FLAC, M4A and AAC and 7 more formats — free, in batches, files up to 10 GB, with no sign-up and no watermark.
Drop your AU file
Choose the format you need
Download the result
Choose file
or drag & drop — audio or video files
Free · Unlimited · No sign-up · Max 10 GB
Your privacy is our mission. Most files are converted right in your browser and never leave your device. Only large files, or formats a browser cannot process, are sent to our server over an encrypted connection — they are never stored, never shared, and deleted as soon as your download is ready.
What Is an AU File?
AU is the simple audio format of Sun and NeXT workstations, and one of the first sound formats used on the web. It is still found in Java programs and old Unix archives. AU is lossless: it stores the audio without discarding anything, at the price of larger files.
AU Facts
| Full name | Sun/NeXT Audio |
|---|---|
| File extension | .au, .snd |
| Type | Audio |
| How it stores data | Uncompressed PCM or µ-law |
| Created by | Sun Microsystems |
| Best for | legacy Unix and Java software |
| Watch out | rarely supported by current consumer players |
| Opens with | VLC, Audacity, QuickTime |
How to Open an AU File
A .au file opens with VLC, Audacity, QuickTime. If none of those is at hand — or the file has to go into a program, device or website that refuses AU — convert it: MP3, WAV and OGG are the usual choices.
Convert AU to Another Format
Convert Other Formats to AU
Frequently Asked Questions
What is an AU file?
AU is the simple audio format of Sun and NeXT workstations, and one of the first sound formats used on the web. It is still found in Java programs and old Unix archives.
How do I open a .au file?
With VLC, Audacity, QuickTime. If your device or program does not accept it, convert the file to a format it does.
How do I convert an AU file?
Drop the file into the converter on this page, choose the target format — MP3, WAV, OGG, FLAC and M4A and others — and press Convert. It is free, there is no account and several files can be converted at once.
Is AU lossy or lossless?
AU is lossless: it stores the audio without discarding anything, at the price of larger files.
What is AU good for, and what are its limits?
Best for: legacy Unix and Java software. Watch out: rarely supported by current consumer players.
Is the AU converter free, and how big can the files be?
It is free, with no account, no watermark and no daily limit. Files can be up to 10 GB each.
Which formats can be converted to AU?
MP3, WAV, OGG, FLAC, M4A, AAC, ALAC, AIFF, AMR, AC3, CAF and GSM and 16 more.