Convert M4B to Opus Online — Free
Fast, free M4B to Opus converter. No registration required.
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How to Convert
Upload your .m4b file by dragging it into the upload area or clicking to browse.
Choose your output settings. The default settings work great for most files.
Click Convert and download your .opus file when it's ready.
What is M4B?
M4B is the MPEG-4 audiobook format used by Apple iTunes and many audiobook platforms. It supports chapter markers, bookmarking, and AAC compression for efficient audiobook delivery.
Format Details
- Full Name
- MPEG-4 Audiobook
- Extension
- .m4b
Key Features
- Chapter support
- Bookmark resume
- iTunes compatible
- AAC compression
What is Opus?
Opus is a modern audio codec designed for interactive speech and audio transmission. It provides excellent quality at low bitrates and is widely used in VoIP and streaming.
Format Details
- Full Name
- Opus Audio Codec
- Extension
- .opus
Key Features
- Low latency
- Excellent compression
- Voice optimized
- Open source
M4B vs Opus
| Feature | M4B | Opus |
|---|---|---|
| Full Name | MPEG-4 Audiobook | Opus Audio Codec |
| Extension | .m4b | .opus |
| Best For | Chapter support | Low latency |