Octavo
Try it on one book, free
- 1 book
- Base monthly AI usage
- 3 research files, up to 5 MB each
- 3 saved versions
- PDF export with a Chaptora cover page
One quiet place for the whole book. It knows every chapter and source, and shows each change in red and green for you to keep or reject.

Ten steps with one manuscript, from the first chapter to a book that is ready for print.
Every chapter, front matter to back, open in one window.
Names in your pages become characters, places and the ties between them.
Drop in a PDF or a link. It is read, indexed and ready to quote.
Give the assistant a goal in plain words, the way you would brief an editor.
Your chapters, your cast and the new interviews, before a single line changes.
Every change lands in your text in red and green. Keep or reject each one.
Accept one change at a time. Each one settles into ink, and the count goes down.
Point at a citation and see the page it came from. The footnotes follow.
One click turns the manuscript into the printed book: running heads, folios, drop caps.
A print-ready PDF at your trim size, an EPUB, or Word for your editor.
| Feature | Pricing | ![]() | |||
|---|---|---|---|---|---|
| Chapters you can organise and reorder | |||||
| AI writing help built in | Bring your own AI key | ||||
| Story bible the AI reads (characters, places) | |||||
| AI agent that carries one goal across many chapters | Chat output pasted in by hand | No built-in AI | No built-in AI | ||
| Every AI edit shown in red and green to keep or reject | Diff in Quick Edit only | Apply or Discard, no diff | No built-in AI | No built-in AI | |
| AI that reads your own research (PDFs, web pages) | Text documents only | Notes typed into the Codex | Keeps research files; no AI | No built-in AI | |
| AI answers that name the sources they used | No built-in AI | No built-in AI | |||
| Footnote citations and a generated bibliography | Footnotes; bibliography via other apps | Footnotes; bibliography typed by hand | |||
| Word (DOCX) export | |||||
| EPUB ebook export | |||||
| Print-ready PDF for self-publishing | |||||
| Preview of the typeset book before you export | |||||
| Free plan, not only a trial | Free trial | 21-day trial | 30-day trial | 30-day refund |
| Feature | ![]() | |
|---|---|---|
| Chapters you can organise and reorder | ||
| AI writing help built in | ||
| Story bible the AI reads (characters, places) | ||
| AI agent that carries one goal across many chapters | ||
| Every AI edit shown in red and green to keep or reject | Diff in Quick Edit only | |
| AI that reads your own research (PDFs, web pages) | Text documents only | |
| AI answers that name the sources they used | ||
| Footnote citations and a generated bibliography | ||
| Word (DOCX) export | ||
| EPUB ebook export | ||
| Print-ready PDF for self-publishing | ||
| Preview of the typeset book before you export | ||
| Free plan, not only a trial | Free trial |
Sources checked 8 November 2026, on each tool’s own pages.
Compare all book writing toolsTry it on one book, free
For the book you mean to publish
For heavy research and daily agent work
Prices in USD, excl. VAT.
Yes, if you want it to.
Chaptora can draft whole chapters from your outline, sources and voice sample, or work beside you on a single passage, a tighter paragraph or a fact check. Every change lands in your text in red and green, and you keep or reject each one. How much you hand over is up to you.
It works from a page of your own prose and your writing rules, and it avoids machine-text habits such as stated feelings and tidy closing summaries.
Paste a voice sample once and Chaptora follows its rhythm and sentence shape. Where your style breaks a rule on purpose, your style wins. New prose stays in the language of your chapters.
Never.
Your chapters and sources are used only to answer you, never to train any model, and never shared. The book lives in your Chaptora account, saved as you type, with your uploads stored privately beside it. Export a copy whenever you like; deleting the book deletes everything in it.
Yes.
Import a Word manuscript or pasted text and Chaptora splits it into chapters. You check titles, order and the split before anything is created. Paragraphs, headings, bold, italic, lists and images come along. Import works on every plan, uses none of your AI allowance, and the uploaded file is discarded afterwards.
Chaptora handles both.
Novels get characters, places and a timeline in a canon that a scan checks for contradictions. Non-fiction gets uploaded research, footnote citations, a Chicago bibliography and answers that name the sources they used. Print layout and export work the same for both, and you can write in any language.
One book, three research files, monthly AI usage and PDF export with a Chaptora cover page.
Octavo is free with no credit card and includes the agent; research files can be up to 5 MB each, with three saved versions. Quarto and Folio add unlimited books, EPUB and Word export and more usage. The pricing page lists every limit.