Best AI tool for summarizing a long PDF: ChatGPT vs Claude vs Gemini vs Gemini Notebook

Four tools you may already have, compared on what their own help pages say about long PDFs: size limits, charts, checking answers against the page, and what happens to your file.

Sources read: 2026-10-24 · Plans and limits change; check the linked pages.

Bottom line

Best for most people: Gemini Notebook. It is free to start, and it is the only one of the four whose help pages say answers come with in-line citations to your document, so you can check each point.

Best if you already use ChatGPT, Claude or Gemini: upload the PDF to the one you have, ask for page numbers, and open those pages yourself before you act.

How they compare

What each vendor's help pages say, read on 2026-10-24. Numbers in brackets link to the source list below.

ChatGPT, Claude, Gemini, Gemini Notebook: documented PDF features
Feature	ChatGPT	Claude	Gemini	Gemini Notebook
File size	Up to 512 MB per document; text and document files are capped at 2 million tokens each. [1]	Up to 500 MB per file in a chat (30 MB for files added to a project). [3]	Up to 100 MB per file (videos have a separate limit). [5]	Up to 200 MB or 500,000 words per source. [7]
Page limit	No page limit stated; the 2 million token cap per file applies. [1]	PDFs up to 1,000 pages. [3]	No page limit stated. Google says the 1 million token context window on Google AI Pro or Ultra can take in up to about 1,500 pages of text. [5]	No page limit stated; the 500,000-word limit per source applies. [7]
Files at once	Up to 80 file uploads every 3 hours; OpenAI may lower this at peak times. [1]	Up to 20 files per chat. [3]	Up to 10 files per prompt (subject to availability). [5]	Up to 50 sources per notebook for free users. [7]
Charts and images in the PDF	Reads text and images in PDFs, including charts and diagrams, when you attach the PDF directly to the chat. [1]	Reads text and visuals in PDFs of 100 pages or fewer; text only for 101 to 1,000 pages. [3]	Not stated on the help page. [5]	Not stated on the help page. [7]
Free plan	Uploads work on the free plan, limited to 3 file uploads per day. [1]	A free plan exists; the upload help page does not state per-plan upload limits. [3][9]	Sign-in required; paid Google AI plans give higher upload limits. [5]	Free users get up to 50 sources per notebook. [7]
Points you back to the page	Not documented for uploaded files. Ask for page numbers and check them. [1]	Not documented. The help page says to use your PDF viewer's page numbers when you refer to pages. [3]	Not documented for uploaded files. Ask for page numbers and check them. [5]	Answers include in-line citations to your sources. [8]
Your data (personal accounts)	On Free, Plus and Pro, chats can be used to train models by default; turn off "Improve the model for everyone" in Data controls. Business plans are not used for training by default. [2]	Chats are used to improve models only if you allow it in your privacy settings, or if they are flagged for safety review. Incognito chats are not used. [4]	With Keep Activity on, chats and uploads are used to improve Google services, including training, and some are read by human reviewers. Turn Keep Activity off or use a temporary chat. [6]	Not used to train unless you give feedback. Work and school (Workspace) accounts are not reviewed by people or used to train models. [8]

When to pick each

Gemini Notebook

You need to check every point against the document, or you are working from several documents at once.

ChatGPT

The PDF has charts or diagrams you need explained, or it is a very large file. On the free plan you get 3 uploads a day.

Claude

You have a long report of up to 1,000 pages. Charts and images are only read in PDFs of 100 pages or fewer.

Gemini

You already use Google and want to add several files (up to 10) to one prompt. Google notes that very large uploads can miss details, so split long documents or use a paid plan.

Work in PDFs all day? Acrobat's own AI assistant summarizes inside the PDF app (paid Acrobat option). See Adobe Acrobat AI Assistant / Acrobat.

Try this prompt

Copy it into the AI assistant you use and replace the [brackets].

I've uploaded a PDF. I'm a [your role] and I need to decide [decision]. Give me:
1) BLUF: the bottom line in 2 sentences.
2) The 5 key insights, each with the page or section number.
3) Anything I should double-check, or that's missing from the document.
Only use the document; if something isn't in it, say so. Keep it under 250 words.

Step-by-step instructions: Summarize a long PDF and find what matters.

How this guide was prepared

This comparison is based on each vendor's published help and privacy pages, read on 2026-10-24. Promptivity has not independently tested these tools hands-on for this job. No tool paid to appear, there are no affiliate links, and Promptivity's own products are not included.

Limitations

Limits, plans and data settings change often. Everything in the table was read on the vendors' help pages on 2026-10-24; confirm on the linked page before you rely on it.
Promptivity has not tested these tools hands-on for this job. This page compares documented features only and does not measure summary quality.
Any AI summary can miss or misstate details, and page numbers can be wrong. Open the pages behind anything you will act on.
Work and school accounts can have different limits and data terms; check with your organization.
Prices are not shown here. See each tool's page for its recorded price and the date it was checked.

Sources

Uploading files and audio to ChatGPT, OpenAI Help Center. Accessed 2026-10-24.
Data controls in ChatGPT, OpenAI Help Center. Accessed 2026-10-24.
Upload files to Claude, Claude Help Center. Accessed 2026-10-24.
Is my data used for model training?, Anthropic Privacy Center. Accessed 2026-10-24.
Upload & analyze files in Gemini Apps, Gemini Apps Help. Accessed 2026-10-24.
Gemini Apps Privacy Hub, Gemini Apps Help. Accessed 2026-10-24.
Add or discover new sources for your notebook, Gemini Notebook Help. Accessed 2026-10-24.
Learn about Gemini Notebook, Gemini Notebook Help. Accessed 2026-10-24.
Claude pricing, Anthropic. Accessed 2026-10-24.

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