.AU file extension
To open .AU files on Windows, right-click the .AU file and select 'Open with'.
.AU files are audio files that can be opened using compatible audio software. To open a .AU file, use a media player that supports this format.
Last updated: March 19, 2026 · Reviewed by Julian Stricker
Open on your device
Choose your operating system for a dedicated step-by-step opening guide.
How to open .AU files
Use these platform-specific instructions to open .AU files safely.
Windows
- Right-click the .AU file and select 'Open with'.
- Choose a compatible media player like VLC or Windows Media Player.
Mac
- Control-click the .AU file and select 'Open With'.
- Choose a compatible app such as VLC or QuickTime Player.
Linux
- Right-click the .AU file and select 'Open with'.
- Choose an audio player like VLC or Audacious.
iOS
- Open the .AU file in the Files app.
- Share it to a compatible app like VLC for playback.
Android
- Locate the .AU file in your file manager.
- Open it with a media player app like VLC.
Security notes
- Only open .AU files from trusted sources.
- Scan files for malware before opening.
- Avoid executing any embedded scripts within the file.
Recommended antivirus software
Scan files before opening them. These antivirus tools help protect against malware and viruses.
Avast offers free and premium antivirus software that protects against viruses, malware, ransomware, and phishing. Scan files before opening them to ensure safety.
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Can't open this file?
These are the most common causes and fixes when .AU files fail to open.
Common reasons
- File won't open
- Poor audio quality
Fix steps
- Ensure a compatible audio player is installed.
- Check the file integrity and re-download if necessary.
OS-specific troubleshooting
Convert .AU to other formats
Use conversion tools to change .AU files into formats your software supports.
- .AU → .AA
- .AU → .AAC
- .AU → .AAC
- .AU → .AAX
- .AU → .AC3
- .AU → .AC3
- .AU → .AIF
- .AU → .AIFF
- .AU → .AIFF
- .AU → .ALAC
- .AU → .AMR
- .AU → .APE
- .AU → .CAF
- .AU → .CUE
- .AU → .F4A
- .AU → .FLAC
- .AU → .FLAC
- .AU → .M4A
- .AU → .M4A
- .AU → .M4B
- .AU → .M4B
- .AU → .M4R
- .AU → .M4R
- .AU → .MKA
- .AU → .MKA
- .AU → .MP2
- .AU → .MP3
- .AU → .MP3
- .AU → .MPA
- .AU → .OGG
- .AU → .OGG
- .AU → .RA
- .AU → .RAM
- .AU → .WAV
- .AU → .WAV
- .AU → .WMA
- .AU → .WMA
What is a .AU file?
.AU is an audio file format originally developed by Sun Microsystems. It is commonly used for simple audio recordings and is supported by various audio playback applications.
Background
.AU files were developed by Sun Microsystems and are primarily associated with the Unix operating system. They were one of the first audio file formats used on the internet and are still supported by many audio playback applications today. The format typically contains simple audio data and is recognized by its '.au' file extension.
The AU format is known for its simplicity and was historically used in early web applications for embedding sound clips. It is less common today but remains supported by many modern audio players due to its historical significance and straightforward structure.
Users may encounter .AU files when dealing with legacy systems or older audio archives. Despite newer formats offering better compression and quality, the .AU format is still useful for basic audio playback and compatibility with older software.
Common MIME types: audio/basic
Further reading
Authoritative resources for more details on the .AU format.
Common .AU issues
File won't open
The file may not open if the required software is not installed or the file is corrupted.
- Ensure a compatible audio player is installed.
- Check the file integrity and re-download if necessary.
Poor audio quality
The audio quality might be subpar due to the file's original encoding.
- Try playing the file in a different audio player.
- Convert the file to a more modern format using an audio converter.
FAQ
Can I convert .AU files to another format?
Yes, use an audio conversion tool to convert .AU files to formats like MP3 or WAV.
Why does my .AU file sound distorted?
Distortion can occur if the file is corrupted or if the audio player does not fully support the format.
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