In depth
Everything you need to know about extracting EPUB chapters
An EPUB is a zipped set of web pages plus a table of contents. In a reader app it looks like one book; as a producer you need the parts: how many chapters there are, what they're called and how long each one is. An EPUB chapter extractor gives you that list without unzipping anything by hand.
The extractor above reads the file in your browser and shows every chapter it finds with a word count and an estimated audio time. It finds chapters the same way FullCastBook's studio does when you import a book, so the list is a fair preview of the chapters you would get there.
Extract chapters from an EPUB in your browser
Drop the file and the EPUB chapter extractor opens the package, follows its spine (the reading order) and takes chapter titles from the table of contents: the navigation document in EPUB 3, or the older NCX file in EPUB 2. A file with no contents entry takes its title from its first heading.
Publishers often split one chapter across several files to keep each file small. When a file has neither a contents entry nor a heading of its own, the extractor joins it to the chapter before, so a chapter spread over three files still appears once, with one word count.
DRM-protected EPUBs, which include many store purchases, are encrypted and can't be read, and the extractor doesn't remove DRM. Use your own manuscript, a DRM-free purchase or a public-domain book.
Word count and estimated audio time per chapter
Word count by chapter is the number narrators and producers plan around. ACX, Audible's production platform, says most narrators record about 9,300 words per finished hour, which is 155 words a minute, the pace used here. At that rate a 3,000-word chapter runs about 19 minutes, a 6,000-word chapter about 39 and a 12,000-word chapter about 77.
The spread tells you more than the average. A book of 30 even chapters is easy to schedule and easy to listen to; a book where one chapter runs four times longer than the rest might need a break added. For the length of the whole book in hours, use the audiobook length calculator.
Front matter and back matter, set aside
Cover pages, copyright notices, tables of contents and other near-empty sections are part of the EPUB, but they mean little read aloud and, with AI narration, only add cost. The EPUB chapter extractor sets them aside by default and lists them under a separate heading, so nothing disappears without you seeing it. In the studio you can add any of them back.
Some sections are a judgement call: a dedication, an author's note or acknowledgements. Stores expect short spoken credits rather than the printed front matter; ACX, for example, asks for opening and closing credits as separate files, with the title, author and narrator stated at the start.
Split an EPUB into chapters: what you get
If you came to split an EPUB into chapters, the list is the map: titles, order and size, plus the totals for the whole book. Copy it to the clipboard or download it as a TXT file to paste into a spreadsheet, a production schedule or an email to a narrator.
The EPUB chapter extractor exports that list, not the chapter text or new EPUB files. To turn the chapters themselves into audio, the same file goes into the studio, where each chapter becomes its own track. Used that way, it's the planning half of an audiobook chapter splitter.
Also works with DOCX, PDF, TXT and Markdown
Word files are split at the top heading level they use, usually Heading 1. PDFs need a text layer, since scans without one can't be read; page numbers are dropped and chapters found from lines like "Chapter 1", "Part Two", "Prologue" or "Epilogue". TXT files follow the same rules, and Markdown files split at their headings.
A text with no recognisable headings is cut into parts of about 20,000 characters at paragraph breaks. If you see "Part 1, Part 2" instead of your chapter titles, that's the cue to add headings to the source.
Next: turn the chapters into an audiobook
When the list looks right, the same file can go into FullCastBook. The studio detects the chapters, finds every speaking character and gives each one a voice next to the narrator, then exports one MP3, an M4B with chapter markers or a ZIP with a file per chapter. See EPUB to audiobook for the full walkthrough. New accounts get free credits for a short sample chapter, and plans are on the pricing page.
