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AU to AAC - Online Audio Converter
Convert AU to AAC online. Private, client-side - no uploadrequired. Batch conversion, quality presets, codec control.
Convert AU to AAC
Drop AU audio here or click to select
AU
AAC (AAC)
About AU to AAC
Convert AU to AAC. AU is Sun's simple container, usually holding 8 kHz telephony audio. AAC is the MPEG-4 successor to MP3 used by YouTube and Apple Music. Container variants (ADTS, MP4) need matching extensions on export..
Why convert AU to AAC?
- Smaller files with AAC lossy compression.
- Keep quality where supported.
- Private, no upload - runs in your browser.
AU vs AAC
| Codec | PCM 16-bit | AAC |
|---|---|---|
| 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. | AAC is the MPEG-4 successor to MP3 used by YouTube and Apple Music. |
When not to convert AU to AAC
- Skip AAC 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 AAC 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. Container variants (ADTS, MP4) need matching extensions on export. Encode AAC (AAC) 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 AAC?
Drop your AU file onto this page, choose quality and codec settings, then click Convert. The result downloads as AAC instantly. All processing runs in your browser.
What codec is used for AAC?
The default codec for AAC is AAC. 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.