M4B to MP3
Split an M4B audiobook into per-chapter MP3 files, right in your browser — perfect for players that do not support M4B. Your files never leave your device.
Drop an M4B, or click to browse
M4B · M4A · one file · split into per-chapter MP3s
How M4B to MP3 splitting works
Drop a finished M4B and the tool reads its chapter markers, re-encodes each chapter to an MP3 at the bitrate you pick, tags it with the chapter title and track number, and bundles the set into a ZIP. A file without chapters becomes a single MP3. Everything runs locally through a WebAssembly build of FFmpeg — nothing is uploaded.
M4B to MP3: common questions
- Does each chapter become its own MP3?
- Yes. Each chapter in the M4B is exported as a separate MP3, named and numbered by chapter, and the files are bundled into a single ZIP for download. If the M4B has no chapters, the whole book is exported as one MP3 instead.
- Why convert an M4B to MP3?
- MP3 plays on virtually any device and app, including older players and car stereos that do not understand M4B. Splitting by chapter also makes it easy to re-organise, edit, or load individual sections.
- Will splitting reduce the audio quality?
- The chapters are re-encoded to MP3, so there is a small generational loss as with any re-encode. For spoken word, 64 kbps is transparent; choose 96 or 128 kbps for recordings with music or effects.
- Are my files uploaded anywhere?
- No. Splitting runs entirely inside your browser using a WebAssembly build of FFmpeg. Your audiobook never leaves your device. Open your browser's Network tab while splitting to verify there are no uploads.
- Do the MP3 files keep their titles and tags?
- Yes. Each MP3 gets the chapter title, a track number, and the book title and author as album/artist tags, so they stay ordered and identifiable in your library.