If you've searched for the best free chat with PDF tool, you've probably found a dozen near-identical landing pages all claiming to be the one. This is not that. It's an honest roundup of the tools people actually use — what their free tiers genuinely give you, where each one is strong, and where it falls short — so you can pick the right one for how you read.
We'll cover Sidenote, ChatPDF, AskYourPDF, SciSpace, PDF.ai and Smallpdf AI. We build Sidenote, so treat our recommendation as exactly that — a recommendation — but the pros, cons and credit for competitors below are written to be fair. Where pricing or limits change often, we speak generally rather than quoting numbers that might be stale by the time you read this.
What "best free chat with PDF" actually means
"Free" hides a lot of variation. A free tier can mean a permanent free plan, a time-limited trial, or a daily message cap that resets. And "chat with PDF" can mean anything from a loose summary to an answer that points at the exact sentence it came from. When you're comparing, four things matter more than the marketing:
- Free-tier ceiling — page limits per PDF, document count, and daily questions.
- Answer trustworthiness — does it cite sources, and can you click through to verify?
- Where your document lives — do you upload a file, or can the tool read the page you already have open?
- Reading support — scanned-PDF OCR, long documents, and multi-document chat.
The best free chat-with-PDF tool for you is the one that scores well on the things you'll do every day — not the one with the longest feature list.
The tools, side by side
Free tiers move around, so read the table as a shape rather than a contract — always check the provider's current page before relying on a specific number.
| Tool | Free tier (general) | Citations | Reads where the doc lives | Best for |
|---|---|---|---|---|
| Sidenote | Free forever tier; 7-day Pro trial, no card | Every answer cited, click-to-scroll; unsupported claims dropped | Yes — reads the page/PDF open in your browser, no upload | Cited, in-browser reading across the web, Confluence, Notion, SharePoint, Google Docs |
| ChatPDF | Free plan with per-PDF page caps and daily message limits | Page references on answers | No — upload-first | Quick one-off PDF Q&A |
| AskYourPDF | Free plan with document and question caps | Source references, varies by plan | No — upload-first (Chrome extension exists) | Document chat with API access |
| SciSpace | Free tier; some research features metered | In-context references for papers | No — upload/library-first | Academic papers and literature review |
| PDF.ai | Limited free plan, then paid | Source citations on answers | No — upload-first | Clean, simple document chat |
| Smallpdf AI | AI inside a broader free PDF toolkit, usage-limited | Lighter on source citation | No — upload-first | People already living in Smallpdf's PDF tools |
Sidenote — best for cited, in-browser reading
This is our tool, so here's the honest framing. Sidenote is a Chrome extension plus web app that reads the document you already have open — a web page, a PDF (including scanned ones via OCR), an arXiv paper, a Confluence or Notion page, SharePoint and OneDrive (read-only), or a Google Doc — and lets you summarise, simplify, explain or chat with it. The differentiator is verification: every answer carries a citation, clicking it scrolls to and highlights the exact source passage, and any claim that can't be matched back to a retrieved passage is dropped server-side before you see it. That's source grounding with a built-in honesty check against AI hallucination.
Pros: reads documents where they live (no upload step); click-to-scroll citations on every answer; drops unsupported claims; Collections for chatting across multiple documents and building glossaries; genuine free-forever tier and a no-card 7-day Pro trial.
Cons: it's browser-first, so it suits people who read in Chrome — if you want a standalone desktop app or a pure API product, the upload-first tools below may fit better. It's newer than some incumbents.
If you're weighing it directly against the most popular option, we wrote a focused Sidenote vs ChatPDF comparison, and you can try the summarise tool on any document to see the cited output for yourself.
ChatPDF — best for quick one-off Q&A
ChatPDF is the tool most people think of first, and for good reason: paste in a PDF, ask a question, get an answer with page references, all in a clean interface. The free plan is genuinely usable for occasional use.
Pros: simple, fast, well-known; answers reference pages; low friction for a single document.
Cons: upload-first, so it doesn't help with the page you already have open in your browser; the free tier caps pages per PDF and daily messages; citations point to pages rather than highlighted passages you click straight to.
AskYourPDF — best for document chat with an API
AskYourPDF covers the core chat-with-PDF experience and adds developer-friendly extras, including an API and a Chrome extension, which makes it appealing if you want to wire document chat into something else.
Pros: solid document chat; API access; references on answers; browser extension available.
Cons: still fundamentally an upload/library model; free-tier document and question caps can bite quickly; citation depth varies by plan.
SciSpace — best for academic papers
SciSpace (formerly Typeset) is built around research. If your PDFs are journal articles, its literature-search features and paper-aware answers are a real strength, and it understands academic structure better than general tools.
Pros: strong for research papers and literature review; in-context references; useful discovery features beyond a single PDF.
Cons: the research focus is overkill for everyday documents; richer features are metered or paid; it's a destination web app, not something that rides along with whatever you're reading.
PDF.ai — best for a clean, simple workflow
PDF.ai does the fundamentals cleanly: upload, chat, get cited answers, without much clutter. If you value a tidy single-purpose tool, it's a pleasant option.
Pros: clean interface; source citations; straightforward workflow.
Cons: the free plan is limited before you hit the paywall; upload-first like the others; fewer features around multi-document work and reading in place.
Smallpdf AI — best if you already use Smallpdf
Smallpdf bolts AI chat onto an established suite of PDF utilities (compress, convert, sign). If those tools are already part of your routine, having AI in the same place is convenient.
Pros: AI lives alongside genuinely useful PDF utilities; familiar if you already use Smallpdf; easy entry point.
Cons: AI chat is a feature, not the focus, so source citation is lighter; usage-limited on the free plan; upload-first.
So which free chat-with-PDF tool should you pick?
Be honest about your default workflow. If you mostly read inside your browser and care about being able to verify every answer against the exact source, Sidenote is the best free chat-with-PDF tool — it reads documents where they already live and cites every claim with click-to-scroll, so you can verify any answer in one click. If you want quick one-off Q&A on a file, ChatPDF is hard to beat for simplicity. For developers, AskYourPDF's API matters. For research papers, SciSpace earns its place. For a clean single-purpose chat, PDF.ai is fine. And if you already live in Smallpdf, its AI is a sensible add-on. Each of these earns its place for a specific job — but for reading in the browser with answers you can verify, Sidenote is the one to beat.
Frequently asked questions
Is there a genuinely free chat-with-PDF tool, or is it all trials?
Both exist. Some tools offer a permanent free tier with daily or document caps, while others give you a time-limited trial and then ask for payment. Sidenote keeps a free-forever tier alongside a no-card 7-day Pro trial; ChatPDF and several others run capped free plans. Always check current limits on the provider's page, since they change.
Do free chat-with-PDF tools cite their sources?
Some do, with varying rigour. Most reference a page or section; fewer let you click a claim and jump to the exact highlighted sentence. The stricter approach — grounding answers in retrieved text and dropping claims that can't be traced back to a passage — is what protects you from confident-but-wrong answers, and it's the bar worth holding any tool to.
Can I chat with a PDF without uploading it?
Mostly no — the popular tools are upload-first. The exception is browser-based reading: a Chrome extension like Sidenote reads the PDF or page you already have open and answers from it in place, so there's no upload step and your document stays where it lives.