How to split an audiobook into chapters
Split an audiobook into one file per chapter without re-encoding the audio - and keep a chapter list your player can read.
Audiobooks usually arrive as one long file. If you want one file per chapter - for a phone, a car stereo, a language course, or a picture-book recording - the job is not "cut it into equal lengths". It is "cut it where the chapter actually changes".
What you need
- The audiobook file (M4B, MP3, M4A or WAV all work)
- A browser - nothing to install, and the file never leaves your device
Steps
- Load the file. Open the audio splitter and pick the audiobook. The waveform appears within a second or two, even for a ten-hour book, because the audio is not decoded as a whole.
- Mark the chapter boundaries. Play the book and, at the moment each chapter starts, place a marker. Then place the end marker for that chapter. Every start/end pair becomes one output file. You can drag any marker afterwards to fix a boundary you placed a fraction too early.
- Export. All chapters download in one pass. If you have a lot of them, the ZIP export (Pro) gives you a single download instead of twenty.
Keep the chapter list too
Cutting the audio is only half of it: players need to know where each chapter begins inside the original file. Export the markers as a CUE sheet or as a chapters file (Podcasting 2.0 format) - both Pro exports - and the chapter names, start times and durations travel with the audio.
Why not re-encode?
Re-encoding an audiobook means decoding every frame and encoding it again: it takes minutes, it costs quality, and it can shift the timing slightly. Frame-level copying does none of that - the clips are the original audio, just with new boundaries. That is why a two-hour book splits in seconds instead of minutes.
A note on long files
MP3, WAV, M4A and AAC have no fixed length limit here. FLAC and OGG must be decoded first, which caps them at roughly two hours in a browser tab.