Free Bulk M4B Audio Converter Online — 24+ Formats
Drag and drop your files into this 100% free online M4B converter (audio/mp4, .m4b, Lossy), pick a target format from 24+ options and click the Convert button to change formats in HD quality. Use the quality slider to control file size and detail, then download each result separately or grab the whole batch as a single ZIP — no signup, no downloads, and no watermark needed; your M4B files are deleted from our servers right after. Also see:Bulk WAVE converter.
Drop your M4B files here or click to browse
Convert M4B to MP3, WAV, FLAC, OGG, AAC, M4A and 18+ more formats in HD quality
Choose FilesThis M4B converter supports 24+ output formats with bulk and batch processing — pick your target format directly from the dropdown above. Related:Complete AIFF converter.
What Is M4B Format and Why Convert It Online?
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.
| Property | M4B Details |
|---|---|
| File Extension | .m4b |
| MIME Type | audio/mp4 |
| Compression Type | Lossy |
| Metadata Support | Yes |
| Available Output Formats | 24+ formats |
- Bulk and batch conversion that lets you upload and convert multiple M4B files at once to any of 24+ supported formats
- 100% free with no signup so you can start converting M4B files instantly without creating an account
- Private and secure because all uploaded files are auto-deleted from our servers immediately after conversion