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AU to MP3 - Online Audio Converter
Convert AU to MP3 online. Private, client-side - no uploadrequired. Batch conversion, quality presets, codec control.
Convert AU to MP3
Drop AU audio here or click to select
AU
MP3 (libmp3lame)
About AU to MP3
Convert AU to MP3. AU is Sun's simple container, usually holding 8 kHz telephony audio. MP3 is the MPEG-1 Layer III codec, playable on virtually every device. Repeated re-encoding stacks artifacts; convert from the master..
Why convert AU to MP3?
- Smaller files with MP3 lossy compression.
- Keep quality where supported.
- Private, no upload - runs in your browser.
AU vs MP3
| Codec | PCM 16-bit | libmp3lame |
|---|---|---|
| Compression | uncompressed | lossy |
| Sample behavior | Full quality kept | Quality set by bitrate |
| Typical use | AU is Sun's simple container, usually holding 8 kHz telephony audio. | MP3 is the MPEG-1 Layer III codec, playable on virtually every device. |
When not to convert AU to MP3
- Skip MP3 for archival masters: lossy compression discards detail, so keep the AU original.
- Keep a master copy: repeated exports stack small losses, so archive AU before batch MP3 shares.
Limits
Starting point: AU - AU is Sun's simple container, usually holding 8 kHz telephony audio. Headers are minimal; verify sample rate after conversion. Repeated re-encoding stacks artifacts; convert from the master. Encode MP3 (libmp3lame) from AU at 256k for music or 128k for speech, starting from the master.
How conversion works
Conversion runs entirely in your browser with FFmpeg WASM. Files never leave your device.
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FAQ
How do I convert AU to MP3?
Drop your AU file onto this page, choose quality and codec settings, then click Convert. The result downloads as MP3 instantly. All processing runs in your browser.
What codec is used for MP3?
The default codec for MP3 is libmp3lame. You can change audio parameters in Advanced mode.
How do you store my files?
We do not store any processed audio. All conversion happens entirely in your browser using FFmpeg WASM.