ChatPDF ChatPDF does a great job of quickly extracting information from large PDF files. Try talking to manuals, essays, legal contracts, books or research papers. ChatPDF does not yet understand the images in a pdf and may have difficulty answering questions that require multiple paragraphs to be understood at the same time. The PDF is first analyzed to create a semantic index for each paragraph. When questions are asked, the relevant passages are presented to a ChatGPT-like text generation AI. Your data is saved in secure cloud storage and deleted after 7 days.