Doomreader
AI PDF reader: chat with a PDF or a book, answered from its text
Halfway through a long book, the questions pile up: who was this character again, what does this term mean, what did the author say about it three chapters ago. Doomreader lets you ask the book. Type or speak a question about the PDF, EPUB or free classic you are reading and get a short answer written only from its own text, with the passages it rests on, a tap away.
Asking uses AI credits, 1 a question, which anyone can buy. Reading, listening with your device's voice and everything else in the reader stay free.
How asking works
Open a PDF, an EPUB or one of the free books, and tap the ask button at the top of the screen. Type your question, or speak it where your browser can hear you. Doomreader picks the few passages most likely to hold the answer on your device, never the whole book, and sends them with your question. The answer comes back in a few seconds with the passages it used, each with its chapter, and tapping one takes you to that place in the book.
If the answer is not in those passages, it says so plainly rather than making one up. You can hear the answer read aloud in your device's voice, too.
No spoilers unless you ask for them
By default only the pages up to where you are reading are looked at, so asking who someone is never tells you what happens to them. Tick "use the pages ahead too" when you want the whole book considered, for a textbook or a report where there is nothing to spoil. A saved article is always read whole.
What it is good for
Reminders of who is who in a long Russian novel. A plain explanation of a term in a paper or a contract. What has happened so far, after a week away. Where the author first made the argument you are trying to find. The same works on any article you save, and since one answer is drawn from a handful of passages, it is best at questions about something specific rather than a summary of the whole.
Ask your whole library
Beside the library's search box is a second ask, across every book and article you keep. It looks for the question's words in each book's search index on your device, sends the best passages from several books, and the answer names the book each point comes from. It uses 2 credits a question.
Credits, and who can ask
A question about one book or article is 1 credit, about the library 2. If no answer comes back, the credits are returned. Credits are bought once, 100 or 500 at a time, on the purchase page, are good for 12 months, and do not depend on Pro. There are no free questions: to ask, you sign in with an account whose email is confirmed, and have credits.
The same credits pay for natural AI voices, 1 credit for each 150 words read aloud.
What is sent, and what is not
Unlike most chat with PDF tools, your file is never uploaded. It stays on your device, and only your question and the few passages picked for it, at most about 14,000 characters, go to our server, which has Google's Gemini answer from them on its paid tier, never the free one whose terms let Google use what is sent. Nothing of the question, the passages or the answer is kept.
PDFs need real text to be asked: a scanned PDF, which is pictures of pages, cannot be opened, and a password-locked one neither.