AI PDF Assistant
Upload a PDF and chat with AI — summarize, extract data, translate, and ask questions.
AI Assistant
Upload a PDF and ask anything about it
Upload your PDF
Drop in any PDF — reports, contracts, research papers, ebooks, or manuals.
Ask anything
Type your question in plain English. Ask for a summary, a specific fact, a comparison, or an explanation.
Get instant AI answers
AI reads your document and answers with specific page references. Ask follow-up questions naturally.
Why SynthPDF?
Powered by Claude AI
Answers are generated by Anthropic's Claude — one of the most accurate LLMs for document understanding. Grounded strictly in your document.
Understands meaning, not just words
Ask 'what are the payment terms?' and AI finds the clause even if it uses words like 'invoicing schedule' and 'net 30' — not the phrase you typed.
Any PDF, any length
Research papers, contracts, manuals, annual reports — any text-based PDF up to 25 MB on the free plan. Scanned PDFs are OCR'd automatically.
Full conversation memory
Ask follow-up questions naturally. The AI remembers the entire conversation, so you can build on previous answers without repeating context.
Grounded — no hallucinations
The AI answers only from your document. If the answer isn't in the PDF, it says so. It does not add outside information or invent facts.
Free, no account needed
5 AI uses per day on the free plan. Pro gives 15/day, Max gives 100/day, UltraMax is unlimited.
What Is "Chat with PDF" and Why It's Better Than Ctrl+F
Searching a PDF finds exact words. AI chat understands meaning. Ask "what are the payment terms?" and the AI finds the relevant clause even if it uses words like "invoicing schedule" and "net 30" — not the phrase you typed. It reads the entire document and answers in plain language, with page references.
Best Documents to Chat With
- Research papers and academic articles — ask for key findings, methodology, and limitations without reading 40 pages
- Legal contracts — find specific clauses, obligations, or termination conditions instantly
- Financial reports — extract KPIs, year-over-year comparisons, and risk factors
- Technical manuals — ask step-by-step questions about specific procedures
- Government and policy documents — cut through bureaucratic language to find what applies to you
How the AI Reads Your Document
When you upload a PDF, the AI processes it in three stages:
- Text extraction — all text is extracted from the PDF structure (or OCR'd if scanned)
- Chunking and indexing — the document is split into overlapping sections and indexed for semantic search
- Retrieval-augmented generation (RAG) — when you ask a question, the AI retrieves the most relevant sections and generates an answer grounded strictly in those sections
The AI will not answer from outside knowledge. If the answer isn't in your document, it says so. This is why it's far more reliable than asking a general-purpose chatbot about a specific document.
Tips for Better Answers
- Be specific. "What is the termination notice period?" gets a better answer than "tell me about the contract."
- Ask follow-up questions. The AI remembers the conversation — build on previous answers.
- Request citations. Ask "which page does it say that?" to verify important information.
- Ask for summaries first. Start with "summarize this document in 5 bullet points" to orient yourself before diving into specific questions.
Privacy: What Happens to Your Document
Your PDF is sent to our server for processing — text is extracted and indexed for the AI to query. The document index and your conversation are deleted when your session ends. We do not store, share, or train on your document content. For documents you cannot upload to any server, see our browser-only tools.
Frequently Asked Questions
Any natural language question about the document: 'What are the key findings?', 'Summarize section 3', 'What does the contract say about termination?', 'List all dates mentioned'. The AI understands context and intent.
Yes — scanned PDFs are OCR'd automatically before indexing. Best results with clear, high-resolution scans.
Free users can upload PDFs up to 25 MB or 200 pages. Pro and above support 100 MB and unlimited pages.
The AI is grounded in your document — it cites the source page for every answer and will say 'not found' if the information isn't in the document. It does not add outside information.
Documents are processed server-side for indexing and deleted after your session ends. We do not store or train on your document content.