Convert M4B to OPUS

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

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M4BOPUSRe-encoding

Converting between two lossy formats (M4B → OPUS) involves re-encoding, which may cause additional quality loss. For best results, convert from the original source file when possible.

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 OPUS

OPUS

Opus Interactive Audio Codec

Opus is a modern lossy audio codec optimized for both speech and music. It offers excellent quality at low bitrates and is ideal for real-time communication.

Extension
.opus
Developed By
IETF
Released
2012
Compression
Lossy

Typical Use Cases

VoIPVideo conferencingStreamingWebRTC

Pros

  • • Excellent low-bitrate quality
  • • Low latency
  • • Open source
  • • Versatile

Cons

  • • Limited device support
  • • Newer format
  • • Not all players support it