Convert M4B to AU

Convert M4B files to AU format online for free. No upload required, 100% private.

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M4BAUQuality Note

Converting from M4B (lossy) to AU (Uncompressed) will increase file size but will NOT improve audio quality. The quality lost during the original compression cannot be recovered.

About M4B

M4B

MPEG-4 Audiobook

M4B is an audiobook format based on MPEG-4. It supports chapters, bookmarks, and is the standard format for iTunes and Audible audiobooks.

Extension
.m4b
Developed By
Apple Inc.
Released
2001
Compression
Lossy

Typical Use Cases

AudiobooksPodcasts with chaptersLong-form audio content

Pros

  • • Chapter support
  • • Bookmark support
  • • Good compression

Cons

  • • Limited to Apple ecosystem
  • • Not universal
  • • Requires specific players

About AU

AU

Sun Microsystems Audio

AU is a simple audio format originally developed by Sun Microsystems for Unix systems. It supports both compressed and uncompressed audio.

Extension
.au
Developed By
Sun Microsystems
Released
1980s
Compression
Uncompressed

Typical Use Cases

Unix/Linux systemsLegacy applicationsSimple audio storage

Pros

  • • Simple format
  • • Unix native
  • • Lightweight

Cons

  • • Outdated
  • • Limited features
  • • Poor cross-platform support