AAC to AU - Online Audio Converter

Convert AAC to AU online. Private, client-side - no uploadrequired. Batch conversion, quality presets, codec control.

Convert AAC to AU

[+] Drop AAC audio here or click to select AAC

Output format

AU (PCM 16-bit)

Mode[i]

Simple Advanced

Quality[i]

Sample Rate[i]

Channels[i]

About AAC to AU

Convert AAC to AU. AAC is the MPEG-4 successor to MP3 used by YouTube and Apple Music. AU is Sun's simple container, usually holding 8 kHz telephony audio. Headers are minimal; verify sample rate after conversion..

Why convert AAC to AU?

Larger files than lossy shares with AU uncompressed quality.
Keep quality where supported.
Private, no upload - runs in your browser.

AAC vs AU

Codec	AAC	PCM 16-bit
Compression	lossy	uncompressed
Sample behavior	Quality set by bitrate	Full quality kept
Typical use	AAC is the MPEG-4 successor to MP3 used by YouTube and Apple Music.	AU is Sun's simple container, usually holding 8 kHz telephony audio.

When not to convert AAC to AU

Skip AU for the smallest share: lossless output stays large, so prefer a lossy target when sending AAC files.
Keep a master copy: repeated exports stack small losses, so archive AAC before batch AU shares.

Limits

Starting point: AAC - Efficient lossy audio for streaming services. Container variants (ADTS, MP4) need matching extensions on export. Headers are minimal; verify sample rate after conversion. Encode AU (PCM 16-bit) from AAC 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 AAC to AU?

Drop your AAC file onto this page, choose quality and codec settings, then click Convert. The result downloads as AU instantly. All processing runs in your browser.

What codec is used for AU?

The default codec for AU is PCM 16-bit. 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.