# ChatPDF > Chat with PDFs and other documents to get summaries and cited answers, aimed at students and researchers. ChatPDF is an AI tool for asking questions about PDFs and other documents in a chat interface. ChatPDF summarizes files, answers with citations that link back to the source passage and can handle several documents in one conversation. It works in a web browser, and a free plan covers two documents per day. **Best for:** Students, researchers and professionals who need to extract and verify information from long documents quickly. - Official site: https://www.chatpdf.com - Listed in: [Documents & PDF](https://trendhub.net/ai-tools/category/documents-pdf), [Research & AI Search](https://trendhub.net/ai-tools/category/research-tools), [Summarizer](https://trendhub.net/ai-tools/category/summarizer) - Last checked: 2026-10-09 (facts taken from chatpdf.com) - Source page: https://trendhub.net/ai-tools/chatpdf-chat-pdfs-get-cited-answers ## Key facts - Platforms: Web, API - Pricing model: Freemium - Free plan: Yes - API: Yes ## What is ChatPDF? ChatPDF is a document assistant that lets you upload a file and question it in plain language. Answers appear beside the document, and each one carries citations that jump to the passage it came from, so claims can be checked quickly. Files can be grouped into folders, which allows a single conversation to draw on several sources and compare them. Besides PDFs, the service reads Word, PowerPoint, Markdown and plain text files, and it accepts documents and questions in any language, including mixing the two. The home page also lists tools for summaries, flashcards, slides, AI writing, AI detection and chatting with YouTube videos or websites. Core features can be tried without an account; signing up adds saved history and multi-document chats. A free tier is limited to two documents a day, and a Plus plan removes that limit. A backend API is documented for developers. ## Key features - **Cited Answers**: Attaches references to each reply that scroll the viewer to the matching place in the document. - **Side-by-Side View**: Keeps the conversation and the open file on one screen for quick verification. - **Multi-File Folders**: Combines several documents in one chat so questions can span and compare sources. - **Summaries**: Condenses papers, articles and reports into their main points. - **Multilingual Chat**: Reads documents in any language and replies in the language you choose, even a different one. - **Sharing Links**: Creates a link to a specific PDF that others can open without an account, with access you can revoke. ## Use cases - **Literature Review**: Query a batch of research papers to find methods and results without reading each in full. - **Exam Revision**: Turn lecture notes or a textbook chapter into summaries and flashcards. - **Contract Reading**: Locate clauses in a long legal agreement and check the cited wording. - **Foreign-Language Sources**: Ask questions in your own language about a document written in another. - **Report Analysis**: Pull figures and conclusions from financial reports or manuals. ## Things to know - **Free plan limit**: The free tier analyses two documents per day; unlimited analysis requires the Plus plan. - **Private by default**: Documents stay private unless you generate a sharing link, and that access can be withdrawn later. - **Underlying models**: The site says each request goes to either GPT-4o or GPT-4o-mini. ## FAQs ### What is ChatPDF? ChatPDF is an AI service that lets you chat with PDFs and other documents to summarize them and get answers with citations. ### Is ChatPDF free? Yes. ChatPDF has a free plan that allows analysis of two documents per day. The paid ChatPDF Plus plan offers unlimited document analysis and additional features. ### What file formats does ChatPDF support? ChatPDF reads PDF files along with Word documents, PowerPoint presentations, Markdown and plain text, and the site says the list of formats is growing. ### Do I need an account to use ChatPDF? No. ChatPDF can be tried without signing up. A free account adds saved chat history and conversations across multiple documents. ### Which AI models does ChatPDF use? ChatPDF says each query is sent to either GPT-4o or the smaller GPT-4o-mini, chosen automatically to balance speed and quality. ### Does ChatPDF have an API? Yes. ChatPDF publishes documentation for a backend API that developers can use to work with PDFs programmatically. ### Does ChatPDF work on mobile? Yes. ChatPDF runs in a web browser on desktops, tablets and phones, and the site also lists desktop and mobile apps. ### Is my data secure on ChatPDF? ChatPDF states that documents are encrypted in transit and in storage, kept with a SOC 2 Type II certified storage provider, and can be deleted by the user at any time. --- Source: https://trendhub.net/ai-tools/chatpdf-chat-pdfs-get-cited-answers (trendhub)