Privacy of AI PDF tools: what gets sent where

Updated 13 October 2026 · ChatPDF guides · 8 sources

AI can miss or misstate things. Summaries and answers from AI tools, ChatPDF included, can leave out important details or get them wrong. Check anything that matters against the document itself, especially legal, medical, financial and exam material.

Key points

Most AI PDF tools send your document text and questions to a server and to an AI model provider; few process everything on the phone.
Before uploading, check what is sent, who receives it, how long it is kept, whether it is used for training and how to delete it.
ChatPDF sends the PDF, its text and your questions to its server on Cloudflare, and your question plus relevant passages to Anthropic (or Replicate as a backup). ¹
ChatPDF keeps text passages and a search index until you delete the document; the PDF file itself is not kept after processing. ¹

Uploading a PDF to an AI tool usually means sharing its contents with at least two companies: the app's own service and the company that runs the AI model. That can be fine for a textbook chapter and a bad idea for a medical record or a confidential contract. This guide gives you the questions to ask of any tool, then answers them for ChatPDF.

Six questions to ask any AI PDF tool

What leaves my device? The whole file, the extracted text, only the passages relevant to a question, or nothing?
Who receives it? The app's own servers, a cloud host, one or more AI model providers? Names should be in the privacy policy.
How long is it kept, and in what form? The original file, the text, a search index, the chat history?
Is it used to train AI models? By the app, and by each model provider.
How do I delete it? Is there a delete button that removes server copies, or do you have to email someone?
Do I get asked first? A clear consent step before the first upload is a good sign.

If a privacy policy does not answer these, assume the answer is not in your favor and keep sensitive documents out.

What to keep out of any AI tool

Documents you are not allowed to share: client files, employer confidential material, anything under a non-disclosure agreement.
Health records, identity documents, bank and tax statements, unless you have read the policy and are comfortable with it.
Other people's personal data without their permission.

Removing pages you do not need before uploading reduces what you share. In the Preview app on iPhone you can delete pages from a PDF ²; work on a copy so the original stays intact.

What ChatPDF does with your document

This section describes ChatPDF as set out in its privacy policy ¹.

Where a document goes in ChatPDF, as described in its privacy policy.

Before anything is sent

Before your first upload, an in-app consent screen explains what is sent (the PDF and its text, and your questions), who receives it and how it is used. Without that consent nothing is uploaded, and you can withdraw it later in the app's Settings ¹.

When you add a PDF

The app extracts the text on your iPhone or iPad and uploads that text (not the PDF file itself) to our server, which runs on Cloudflare. The server splits the text into passages and builds a search index; Cloudflare Workers AI builds that index. The PDF file itself never leaves your device ¹. Cloudflare states that it does not use customer content sent to Workers AI to train AI models ³.

When you ask a question

Your question and the relevant passages of the document are sent to Anthropic, whose Claude models write the answer. If Claude is unavailable, they go to Replicate, which runs Meta Llama models, as a backup ¹. Anthropic's commercial terms say it may not train models on customer content from its services, and its privacy center says inputs and outputs from its commercial products are not used for training by default ^4,5. Replicate's documentation says input and output data of predictions created through its API are removed automatically after an hour by default ⁶.

What is kept, and where

On our server: the document's text passages and search index, so you can keep chatting with it, until you delete the document. Data may also be deleted after a long period of account inactivity, as the policy describes ¹.
On your device: your chat history.
Not kept: the original PDF file after processing.

Document content is used to answer your questions and create summaries. It is not sold or used for advertising ¹.

Deleting a document

Deleting a document in the app removes its stored text and search index from our server. You can also ask for deletion of your data by contacting us, as described in the policy ¹. See getting started with ChatPDF for where these controls are.

Private alternatives for sensitive files

If a document should not leave your phone, use the built-in tools instead: search the PDF in Preview ⁷, copy a short passage and summarize it with Apple Intelligence Writing Tools on a supported iPhone ⁸, or read it with the strategies in how to summarize a PDF on iPhone. Apple notes that some Apple Intelligence features use server-side models, so check Apple's own privacy information if that matters to you.

Common questions

Does ChatPDF use my documents to train AI?

We do not sell documents or use them for advertising. Anthropic says it does not train on customer content from its commercial API by default, and Cloudflare says it does not train on Workers AI customer content. ^1,4,3

Is my PDF file stored on a server?

The file itself is not kept after processing. The extracted text passages and a search index are kept so you can keep chatting, until you delete the document. ¹

Can I use ChatPDF without sending anything?

No. Answers are written by AI models on servers, so the document text and your questions have to be sent. Without consent, nothing is uploaded and the app cannot answer questions about your PDF. ¹

Where is my chat history?

On your device. The server keeps the document text and search index, not your chat history. ¹

Sources and further reading

ChatPDF. Privacy Policy. chatpdf.berkcan.dev
Apple Support. Add, delete, rotate, move, or crop PDF pages in Preview on iPhone (iPhone User Guide). support.apple.com
Cloudflare Developers. Workers AI: Data usage. developers.cloudflare.com
Anthropic. Commercial Terms of Service (section B, Customer Content). anthropic.com
Anthropic Privacy Center. Is my data used for model training? privacy.claude.com
Replicate documentation. Data retention. replicate.com
Apple Support. Open and view PDFs and images in Preview on iPhone (iPhone User Guide). support.apple.com
Apple Support. Use Writing Tools to write, improve, and summarize content on iPhone (iPhone User Guide). support.apple.com