Audio
What is a .au file?
A .au file is a NeXT/Sun sound. This is an audio format. Confusingly, this extension has been used by 2 different formats over the years — they're all listed below.
This extension has been used by more than one format
2 different formats have claimed .au over the years, so two files with the same extension aren't necessarily the same kind of thing.
How to open a .au file
- VLC plays almost every audio format ever made.
- Audacity opens it for editing.
The registry records this extension against NeXT/Sun sound, Audacity Audio Block File, so software from that family is the most likely match.
How to convert a .au file
- Export as .mp3 from Audacity or VLC for maximum compatibility.
MIME type
When a .au file travels over the web, servers label it with this MIME type:
audio/basicThe technical record
For archivists, developers and the merely curious: these are the PRONOM registry entries for .au.
| Format name | Version | MIME type | PUID |
|---|---|---|---|
| NeXT/Sun sound | — | audio/basic | x-fmt/139 |
| Audacity Audio Block File | — | — | fmt/1822 |