Free Online MP3 to M4B Converter
Convert MP3 audiobooks to M4B in your browser. Useful when you want a single audiobook-style file in an M4B-compatible container.
Convert your audiobook
The first run downloads the browser conversion engine, so it can take a moment before conversion starts.
What this tool is good for
- Useful for audiobook players that prefer M4B containers.
- Creates a browser-downloaded M4B output without needing desktop software.
- Good for SEO-focused single-file conversion workflows and quick file format cleanup.
Current limits
This converter focuses on file format conversion, not full audiobook metadata rebuilding.
Very large files can take time because conversion happens locally in your browser with FFmpeg WASM.
For now, upload one audiobook file at a time instead of a whole folder.
Conversion log
Useful for checking browser-side progress if a long audiobook takes a while.
No conversion logs yet.
Free Online MP3 to M4B Converter
Audiobooky's free online mp3 to m4b converter is designed as a browser-based utility for quick audiobook file format conversion without installing desktop software. It is especially useful for people who need a fast free online audiobook converter for playback compatibility, testing library imports, or preparing a file for another audiobook app.
Does MP3 to M4B conversion merge multiple files?
Not in this first version. Upload one source file, convert it, and download one converted result.
Will the converted file have chapter markers?
The converter tries to carry over embedded chapter markers from the source file, but it does not generate brand new chapters. If the source chapters are stored in a layout FFmpeg cannot translate cleanly, you may still need the metadata editor afterward.
Related Audiobook Tools
Use these tools when you need to inspect or clean up metadata after conversion.
Helpful References
Primary references for local conversion workflows and audiobook file formats.