Convert AU to M4B
Convert AU files to M4B format online for free. No upload required, 100% private.
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AUM4BSize Reduction
Converting from AU (Uncompressed) to M4B (lossy) will significantly reduce file size. Some audio quality will be lost, but the difference is often imperceptible at higher bitrates.
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
UncompressedTypical Use Cases
Unix/Linux systemsLegacy applicationsSimple audio storage
Pros
- • Simple format
- • Unix native
- • Lightweight
Cons
- • Outdated
- • Limited features
- • Poor cross-platform support
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
LossyTypical 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