ChatPDF vs Explainpaper

ChatPDF lets users summarize documents and ask questions about their contents using conversational AI. Answers include citations that point to references in a PDF, and users can organize files in folders or discuss multiple PDFs in one conversation. It accepts PDFs in any language and supports conversations in any language; listed file types also include Word, PowerPoint, Markdown and text. Sharing links can be created, with access permissions managed or revoked. ChatPDF says documents are encrypted during transfer and storage and can be deleted by the user. Queries are routed dynamically between GPT-4o and GPT-4o-mini. The service works in a browser on any device and is listed for Android, iOS, Linux, macOS and Windows. Its backend API accepts uploaded PDFs or public URLs and lets users query them to build custom PDF chatbots. The API documentation limits each PDF to 2,000 pages or 32 MB and describes the chat API as stateless. The Free plan costs nothing and allows two documents per day.

Explainpaper is a web-based AI reader for research papers. Readers highlight confusing passages to get explanations with adjustable complexity, support for more than 50 languages, and context from the full paper. Paper chat answers questions using the paper’s content, allows follow-ups, and can summarize findings; answers can cite sections so readers can locate relevant material. The product also generates outlines, extracts key points, and shows relationships between concepts. Its free plan is available indefinitely and includes unlimited highlight explanations, follow-up questions, Zotero library import, and basic AI models. Pro costs $16 a month and adds Math Explain for formulas and figures, advanced AI models, whole-paper summaries, saved highlights and explanations, and paper questions. The Pro trial lasts seven days and requires a card. Explainpaper says subscriptions are billed monthly or annually according to the selected plan and payments are processed through Stripe. The product describes its audience as researchers.