Free M4B to MP3 Converter — Right in Your Browser
Split your audiobook into chapter MP3s or one single file. No software to install, no uploads.
For the best experience, use a desktop computer.
Chapters
Conversion happens in this tab. Closing it will stop the process.
Something went wrong
Show details
How to convert M4B to MP3
- Choose your M4B file.
Drag it onto the page or click Choose file. We'll show the chapters, title and author.
- Pick how you want it.
Split into one MP3 per chapter, or make a single MP3. Untick any chapters you don't need.
- Convert and download.
Click Convert to MP3, then download a ZIP of your chapters or your single MP3.
Made for audiobooks, not just audio files
Nothing to install
Works right in Chrome or Edge. No apps, no command line.
Your files stay private
Everything happens on your own computer. Your audiobook is never uploaded.
Keeps your chapters
Split by chapter with the original chapter names, title, author and cover.
Free for single books
Convert a whole audiobook for free — no sign-up, no watermark, no time limit.
Frequently asked questions
What is an M4B file?
M4B is an audiobook format. It's an MP4 audio file (usually AAC) that can hold chapters, a cover and book details in one file. Apple Books and many audiobook apps use it, but some players, car stereos and older devices only play MP3.
Is this M4B to MP3 converter really free?
Yes. Converting one audiobook at a time is free, with no sign-up and no length limit. Pro adds extras like converting many books at once and splitting by time or size.
Are my files uploaded anywhere?
No. The conversion runs inside your browser on your own computer. Your audiobook never leaves your device, which also means there's no upload wait for large files.
Will I lose audio quality?
MP3 and M4B are both compressed formats, so converting means re-encoding. We match the original bitrate (for example 64 kbps) so the difference is very hard to hear for spoken audio.
How long does it take?
It depends on your computer and the length of the book. On a recent laptop, a 10-hour audiobook usually takes a few minutes. You'll see a progress bar and the time left.
Can I convert Audible (AAX) audiobooks?
No. AAX and other copy-protected (DRM) files are not supported. This tool works with DRM-free M4B files, such as those from LibriVox or files you created yourself.
My M4B has no chapters. Can I still convert it?
Yes. You can convert it to a single MP3. If you want it cut into equal parts (for example every 60 minutes), that's available with Pro.
Does it work on my phone?
The page works on phones, but audiobooks are large files, so a desktop or laptop computer with Chrome or Edge gives the best results.