Bulk M4B to CAF Converter Online — Free HD Quality
Drag and drop your multiple M4B files into this 100% free online M4B to CAF converter (.m4b to .caf), and click the Convert button to bulk convert them to CAF format in HD quality. Use the quality slider to fine-tune your CAF output, then download your converted files one by one or as a single ZIP — no signup and no downloads needed, and your original M4B files are removed from our servers right after. Also see:Free APE to FLAC - no account needed.
Drop your M4B files here to convert to CAF, or click to browse
Converts .m4b to CAF (.caf) in HD quality — bulk, free, no signup
Choose FilesM4B vs CAF — File Format Comparison
See how M4B and CAF compare across file extension, MIME type, compression, and feature support. Related:Best M4B to 3GA converter online.
| Feature | M4B | CAF |
|---|---|---|
| File Extension | .m4b | .caf |
| MIME Type | audio/mp4 | audio/x-caf |
| Compression Type | Lossy | Lossless |
| Metadata Support | Yes | Yes |
What Is M4B Format?
MPEG-4 Audiobook — AAC audio in an MP4 container with bookmarking support, the standard format for audiobooks on Apple Books, Audible exports, and iPhone podcasts. See also:Free M4B to WAVE converter.
- Compression: Lossy
- Tags & Metadata: Supported
What Is CAF Format?
Core Audio Format — Apple's flexible container for macOS and iOS supporting any codec (AAC, ALAC, PCM, MP3) with no file-size limit, used internally by Xcode, Logic Pro, and macOS system sounds.
- Compression: Lossless
- Tags & Metadata: Supported