PDF.ai Review: Chat With a PDF for Free (100 Questions a Month)
TL;DR: PDF.ai turns a PDF into a chatbot: upload a document and ask questions in plain English — it answers with citations, and handles any language. The free Hobby plan gives 1 PDF upload and 100 questions a month at $0, no credit card. Useful for digesting one long paper, contract, or report — but only one document, so it’s a specialist tool, not a research library. Paid plans (Pro ~$10–15/month) raise the caps. Best for students and professionals interrogating one dense document fast.
What PDF.ai actually does
PDF.ai (pdf.ai) is a “chat with your document” tool. Upload a PDF and ask questions in natural language: “What are the key findings?”, “Summarize section 3”, “What does the contract say about termination?” Answers come with citations to source passages, so you can verify rather than trust. It reads documents in any language, answers in the language you type, includes OCR for scanned pages, and ships a Chrome extension.
What’s actually free
- 1 PDF upload — one document at a time is the core limit
- 100 questions per month — enough to thoroughly interrogate that document
- 10 MB max file size — fine for papers and reports, tight for large ebooks
- OCR support and cited answers — sources, not just assertions
- Chrome extension included
Heads-up: older 2025 guides list 500 free questions a month; current 2026 guides report 100. The free tier has gotten tighter — verify before building a workflow around it.
What costs money
Pro runs around $10/month billed annually or $15/month billed monthly (from 2026 guides; confirm on pdf.ai/pricing): roughly 100 PDF uploads, 1,000–5,000 monthly questions, 50 MB file size, plus GPT-4 access and higher OCR limits. Higher tiers and a commercial API add-on exist for teams and developers.
PDF.ai vs ChatPDF
Readers of our ChatPDF review will ask: what’s the difference? For casual use they’re near-substitutes:
| Tool | Free plan | Edge | Weakness |
|---|---|---|---|
| PDF.ai | 1 PDF, 100 questions/month, 10MB | Cited answers, multilingual, Chrome extension | One document — no cross-folder research |
| ChatPDF | 2 documents/day | Simpler; more daily documents | Tighter per-document limits |
Free limits change; confirm on each official site.
Pros and cons
Pros:
- Cited answers — every response links back to the source passage, so you can verify
- 100 free questions a month goes a long way on a single document
- Reads PDFs in any language and answers in yours
- OCR included on the free plan — works on scanned pages, not just text PDFs
- No credit card required
Cons:
- One PDF upload on free — no cross-document research without paying
- 10 MB file cap rules out large ebooks and scanned archives
- PDFs only — no Word, Excel, or web pages on the free plan
- Free limits have tightened over time (500 → 100 questions); could tighten again
- The AI can still misread ambiguous passages — check critical claims
Who it’s for
PDF.ai is ideal for students working through a dense reading assignment, professionals parsing one contract or report, and researchers doing a first pass on a paper. Not for literature reviews across many papers (the single-document limit kills that) or anyone who needs the free tier to stay exactly as-is.
FAQ
Is PDF.ai free?
Yes — the Hobby plan is free forever with 1 PDF upload, 100 questions a month, and a 10 MB cap. No credit card required.
Can PDF.ai read scanned PDFs?
Yes — OCR is included on the free plan, so scanned pages work within the 10 MB limit.
Is my document private?
PDF.ai says uploads are encrypted in transit and storage via a SOC 2 Type II certified storage partner. As with any cloud AI tool, don’t upload documents you wouldn’t trust to a third party.
Research-based review — no hands-on testing. Free-tier details and prices checked Oct 9, 2026; verify current terms on the official site before relying on them.