Bulk FLAC to M4B Converter Online — Free HD Quality
Drag and drop your multiple FLAC files into this 100% free online FLAC to M4B converter (.flac to .m4b), and click the Convert button to bulk convert them to M4B format in HD quality. Use the quality slider to fine-tune your M4B output, then download your converted files one by one or as a single ZIP — no signup and no downloads needed, and your original FLAC files are removed from our servers right after. Also see:How to batch convert AAC to M4A?.
Drop your FLAC files here to convert to M4B, or click to browse
Converts .flac to M4B (.m4b) in HD quality — bulk, free, no signup
Choose FilesFLAC vs M4B — File Format Comparison
See how FLAC and M4B compare across file extension, MIME type, compression, and feature support. Related:FLAC to AIFC converter.
| Feature | FLAC | M4B |
|---|---|---|
| File Extension | .flac | .m4b |
| MIME Type | audio/flac | audio/mp4 |
| Compression Type | Lossless | Lossy |
| Metadata Support | Yes | Yes |
What Is FLAC Format?
Free Lossless Audio Codec — open-source lossless compression that reduces file size by 40–60% versus WAV with zero quality loss, perfect for audiophile archiving. See also:Free FLAC to CAF - no account needed.
- Compression: Lossless
- Tags & Metadata: Supported
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.
- Compression: Lossy
- Tags & Metadata: Supported