A textbook you can ask questions.
With the receipts.
A textbook is not a novel — you arrive with a question and need the paragraph that answers it, not a summary of the whole chapter. Chaptera indexes the book down to its sections, figures and tables, then answers from the chapter you are in and shows you the passage it used.
When the book does not answer your question, it tells you so instead of inventing an answer.
Bring the textbook you already have
EPUB, or a PDF — including the scanned, two-column, 700-page kind. A PDF is rebuilt into a navigable book with real chapters and selectable text.
Ask it about the chapter you are on
Answers are scoped to what you are reading, so a question about chapter 3 is not answered out of chapter 11.
Turn it into study material
Summaries, quizzes and flashcards from the section in front of you, plus a vocabulary builder that schedules reviews with SM-2 spaced repetition.
Questions people actually ask
- Will it answer from a chapter I have not read yet?
- Not when you ask about the chapter you are in — answers are scoped to it. You can widen the scope to the whole book deliberately, but it is not the default.
- Does it work on a scanned PDF?
- Yes. Scanned pages are re-OCRed and multi-column layouts are detected and reflowed, so the text reads in the right order and you can select, search and resize it. How good the result is depends on how good the scan is.
- Is the spaced repetition real SM-2?
- In the vocabulary builder, yes — it computes ease factors and intervals with SM-2. Flashcards and quizzes record attempts but do not schedule reviews, and we do not call those spaced repetition.
- Can I get my highlights out?
- Highlights and notes export to Notion, Obsidian, Markdown or JSON. Generated summaries and quizzes do not export yet.
What it does not do yet
You have been sold AI reading tools before. Here is where this one is weak, so you can decide before you spend an evening on it.
- Spaced repetition is in the vocabulary builder only. Quizzes and flashcards track your attempts but do not schedule reviews yet.
- Equations in EPUBs are exact. In a scanned PDF they come from OCR, and a fraction can occasionally come out as the wrong number — check a formula page before you trust it.
- It describes what a figure shows, but it will not read a value off a chart unless the value is printed on it.
- It runs in a browser. There is no native app yet, and it is a private beta.
Free Pro through the end of the year
The first 50 invitations include free Pro through the end of the year. Invitations go out in small batches so I can actually talk to everyone. Tell me what you are trying to read and I will send one — all I ask is that you tell me what breaks.
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