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Asking questions

Get useful answers by asking questions that match the evidence available in your PDFs.

Choose a question scope

The composer defaults to Document, so questions can use evidence from the whole PDF. Choose the current-page button when the answer must stay within the page visible in the PDF viewer; the page is captured when you send the question.

Scope stays with the question

Current-page questions show a page badge in chat history. Regenerating an answer reuses that saved page even if you have since moved the PDF viewer to another page.

Question style

ChatPDF is strongest when questions are specific enough for retrieval to find evidence. Ask for named concepts, clauses, dates, comparisons, or summaries tied to the uploaded document.

Question length

Questions can be up to 4,000 characters long.
  • What are the warranty exclusions in this agreement?
  • Which pages mention revenue concentration?
  • Summarize the evaluation metrics and cite the source pages.

How questions get routed

Before retrieval, a lightweight router rewrites your question into a standalone query and picks one of two modes. These modes are inferred from the question; they are separate from the Document and current-page scope controls in the composer.

Chunks mode

Precise, document-scoped questions use hybrid retrieval over chunks. Current-page questions instead use only chunks overlapping that page.

Summaries mode

Broad, document-wide synthesis (overviews, key findings). Uses page and document summaries.

Want the details?

The full routing, hybrid search, and ranking logic is documented on Retrieval ranking.

When evidence is weak

If retrieval cannot find supporting evidence, ChatPDF says so rather than guessing. Treat a “not enough evidence” reply or missing citations as a signal to refine the question or upload a better source.