Audio Conversion
Convert AU to MP3 Online — Free
Fast, free AU to MP3 converter. No registration required.
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Works Everywhere
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How to Convert
1
Upload your .au file by dragging it into the upload area or clicking to browse.
2
Choose your output settings. The default settings work great for most files.
3
Click Convert and download your .mp3 file when it's ready.
What is AU?
AU is an audio format created by Sun Microsystems. It's one of the oldest digital audio formats, commonly used on Unix and Java platforms.
Format Details
- Full Name
- Sun Microsystems Audio
- Extension
- .au
Key Features
- Unix standard
- Java audio
- Simple format
- Legacy support
What is MP3?
MP3 is the most popular audio format worldwide. It uses lossy compression to reduce file size while maintaining acceptable audio quality for most listeners.
Format Details
- Full Name
- MPEG Audio Layer III
- Extension
- .mp3
Key Features
- Universal compatibility
- Small file sizes
- Streaming support
- ID3 tag support
AU vs MP3
| Feature | AU | MP3 |
|---|---|---|
| Full Name | Sun Microsystems Audio | MPEG Audio Layer III |
| Extension | .au | .mp3 |
| Best For | Unix standard | Universal compatibility |
Frequently Asked Questions
Yes. You can convert up to 5 files per day completely free, with no watermark or registration required.
Most files convert in under 30 seconds. Larger files (over 500MB) may take 1-3 minutes.
No. Our converter uses optimized encoding settings by default to preserve the original quality.
Free users can convert files up to 100MB. Pro users can convert files up to 2GB.
Yes. Our converter works in any modern web browser on any device.