Upload a whole book or textbook to ChatGPT.
EPUB is not among the file types OpenAI names, and a long textbook PDF runs into page and size caps elsewhere. Drop the EPUB or the PDF here: the text is read in your browser and comes back as one text file, with its token count, that any assistant reads.
- EPUB and PDF read in your browser
- Token count shown before you upload
- No sign-up, nothing uploaded to us
Upload only books you have the right to use, such as public-domain titles or your own writing.
Drag your EPUB or PDF here
One book or several, read in your browser.
Where a book stops in ChatGPT, Claude and NotebookLM.
Once a book is text, what is left to check is its size. Before that, what stops it is a format one assistant does not name, or a page or size cap on the PDF.
| Where | What it caps | Limit today |
|---|---|---|
| ChatGPT | EPUB, and one file | EPUB is not a named type; 512 MB and 2M tokens per file |
| Claude chats | A PDF | Up to 1,000 pages and 500 MB; EPUB is read |
| Claude Projects | One file, and the project | 30 MB per file, all of it within the context window |
| Gemini chats | One file | Up to 100 MB |
| NotebookLM | One source | 500,000 words or 200 MB; EPUB is read |
As of September 2026, from the help centers of OpenAI, Anthropic, Gemini and NotebookLM. Every other cap is in the AI file upload limits table.
A whole novel, counted.
Project Gutenberg's EPUB of Pride and Prejudice, 558 KB without images, came back as one text file of 165,531 tokens, estimated, when we ran it on 24 September 2026. That fits a 200K window with room left for your questions.
pride-and-prejudice.epub
558 KB, no images
from gutenberg.org/ebooks/1342Documents: pride-and-prejudice
This is a packed snapshot of a
set of documents...
...Upload a book to ChatGPT in four steps.
- 1
Drop the EPUB or the PDF
One book, or several at once. Each keeps its own name inside the combined file.
- 2
It reads the text here
EPUB chapters and the PDF's text layer become plain text in this tab. Nothing is uploaded to us.
- 3
Check the count against your model
The result shows the token count and the share of a model's context window it takes. Click the model's name to compare another.
- 4
Upload the one text file
Set Format to Plain and download the .txt, a type ChatGPT, Claude and NotebookLM all list. Attach it to a chat or a project, or add it as a NotebookLM source.
Text, not pages
A text file has no page count, so a PDF page cap no longer applies to it. What is left to check is the size and the context window, and the count on the result screen covers both.
Common questions.
- Can ChatGPT read EPUB files?
- EPUB is not among the file types OpenAI's help center names, which lists text files, spreadsheets, presentations and documents such as PDF, DOCX and TXT. A plain text file of the book sidesteps the question: FileConcat reads the EPUB in your browser and hands back one text file that ChatGPT reads like any other.
- How long a book can I upload to ChatGPT?
- OpenAI caps one file at 512 MB and 2M tokens, as of September 2026. Pride and Prejudice came to 165,531 tokens in our test, far under that. The result screen shows your book's count and what share of your model's context window it takes, so you know before you upload.
- Can I upload a textbook PDF to Claude?
- Yes, in a chat, up to 1,000 pages and 500 MB, as of September 2026; Claude refuses a longer PDF. A text file of the same textbook has no page count, so what limits it is the size and the context window instead.
- Can I add a book to NotebookLM?
- Yes. NotebookLM takes EPUB files as sources, each up to 500,000 words or 200 MB, as of September 2026. Several books combined into one file count as one source, as long as the file stays under that cap.
- Can I combine several books or chapters into one file?
- Yes. Drop them together and they come back as one file, each under its own name, with the token count for the whole set.
- Am I allowed to upload a book?
- That depends on the book and on your rights to it, and you are responsible for what you upload. Public-domain books, such as those on Project Gutenberg, and your own writing are the clear cases.
- Is the book uploaded to a server?
- Not to us. FileConcat reads the EPUB or PDF in your browser tab, and there is no account to create. The only upload is the one text file you choose to send to the assistant.
Hand the assistant the whole book.
Text out of a PDF, and what gets lost on the way: converting a PDF to text for an LLM.