Upload a 90-page lease, ask a question, and get an answer that points to the exact page. That’s the basic idea behind AI PDF chat tools. In practice, though, results can vary quite a bit. One tool may pull the right numbers from a scanned tax form, while another gives you a confident answer that doesn’t match the document at all.
So, we compared leading AI PDF chat tools based on accuracy, pricing, file handling, and free-plan limits to find the best tool for chatting with PDF files.
Quick Verdict: What Is the Best Tool to Chat with PDF?
| Tool | Reads scans | Free plan | Paid from | Best for |
| FormsPal PDF Chat | Yes | 10 questions per document, 5 documents daily | $8/mo annually | Checking every answer against the exact sentence |
| ChatPDF | Yes | 2 chats daily | $4/mo annually | Study material, flashcards, and slides |
| SciSpace Chat PDF | Yes | 100 credits monthly | $12/mo annually | Long reports with equations and tables |
| Adobe Acrobat AI Assistant | Yes | About 6 answers, then a paywall | $4.79/mo annually | People already working inside Acrobat |
| Humata AI | Paid plans only | 60 pages, 10 answers | $1.99/mo | Mixed file types: slides, sheets, and links |
| AskYourPDF | Paid plans only | 1 document daily, 50 questions | $11.99/mo annually | Picking your own model, podcast conversion |
| Smallpdf Chat with PDF | No | 25,000-35,000 words per document | $9/mo annually | Fast answers on text PDFs you plan to verify |
Four platforms returned correct facts on every question they completed. The main differences were how far the free plan went and whether scanned PDFs worked without an upgrade.
FormsPal, ChatPDF, SciSpace, and Adobe Acrobat all returned the right facts and clearly said when the documents didn’t contain an answer.
Humata AI and AskYourPDF were accurate with files they could process. However, both restrict OCR on free plans, so our scanned pages couldn’t be tested properly.
Smallpdf was the fastest of the group, but also the only tool to invent a fact - a federal funds forecast the report never gives, complete with page references.
What Is AI PDF Chat and How It Works?
AI PDF chat lets you upload a PDF and ask questions about its contents in natural language. You upload the document, type what you want to know, and the answer comes from text inside that file rather than from general web knowledge. Most platforms cite the page or paragraph behind each response, so you can click through and check the source before you trust it.
Overall, AI PDF chat works best when you need one fact from a long file, a quick summary, or a look at a few sections instead of the whole thing.
Behind the scenes, a PDF AI chat first reads and indexes the document text. It then matches your question with the most relevant passages and uses those passages to generate a response. Some platforms also summarize sections, compare pages, or answer follow-up questions without making you upload the file again.
But the setup has a weak point, and it's the text extraction step. Scanned contracts, password-locked files, and image-only pages give the model nothing to retrieve, so you get a vague reply or a flat refusal. Stronger tools run OCR first and recover most of the content. Weaker ones return an empty answer.
How We Tested AI PDF Chat Tools
Every tool in this comparison had the same test run in the same order, on free plans. The first answer counts, because that's the answer you'd get on your first upload. Three files went into each AI chat with PDF:
- A 7-page room rental agreement with numbered clauses and fill-in fields. This one is structured enough to check every answer against the source text.
- The Federal Reserve's May 2026 Financial Stability Report - 71 pages, tables, and figures with values we verified by hand before testing.
- Scanned pages from a 1915 textile journal. This file is a stress test for tools that must perform OCR before reading a word.
We asked three questions about each file. One requested a summary, one asked for a specific fact with a single correct answer, and one asked for information that wasn’t in the document at all. The final score covered factual accuracy, citations, summary quality, response speed, and free-plan limits.
Best AI Tools to Chat with PDF Files
Here are the AI PDF chat tools that performed best in our tests for accuracy, citations, speed, and overall ease of use.
1. FormsPal PDF Chat
First, FormsPal PDF Chat treats every answer as a claim you can check. Ask a question, and the response arrives with a citation pinned to the exact sentence in your document. Click it, and the built-in viewer jumps to that passage and highlights it on the page.
FormsPal also suggests document-specific questions after upload, giving you a quick starting point when you’re not sure what to ask.
It answered all nine of our test questions correctly. FormsPal pulled the 30-day notice rule from our room rental agreement, summarized the 71-page Federal Reserve report, found the $30,070 billion Treasury figure in a table, and read the scanned 1915 textile journal without requiring a separate OCR.
This AI PDF chat also handled missing information well. When we asked for a rent amount that had been left blank or a forecast the report never provided, the chat said the information wasn’t available.
Key Features
- Citations that highlight the quoted sentence right on the page
- Native reading of scanned and photographed PDFs, no separate OCR step
- Built-in viewer with text selection and search
- No account needed to start
- Files deleted after your session, never used for model training
Free Limits & Pricing
The free plan includes 10 questions per document and 5 documents per day. Membership raises those limits to 60 questions and 50 documents, starting at $8/month billed annually.
2. ChatPDF
ChatPDF is easy to use from the first upload. It gives you a short overview, suggests questions, and can turn the document into flashcards or slides. Answers appear quickly and come with numbered citations that open the source page.
It answered all of our test questions correctly. ChatPDF found the Treasury figure in the Federal Reserve report, pulled the freight charge from the scanned 1915 textile journal, and correctly said when requested information was missing in the room rental agreement. One response referred to "the provided excerpts," though, which may mean longer PDFs are processed in sections rather than read all at once.
The biggest drawback is the free limit. With only two chats per day, it runs out quickly.
Key Features
- Numbered citations linked to source pages
- Support for scanned PDFs
- Flashcard and slide creation
- Fast and Quality response modes
- Mac and mobile apps
Free Limits & Pricing
The free plan includes 2 chats per day. ChatPDF Plus costs $9.99 per month, or $4 per month billed annually, and supports PDFs up to 2,000 pages.
3. SciSpace Chat PDF
SciSpace is built with research in mind. Its PDF chat can explain equations and tables, answer questions about highlighted text, and save useful responses to a notebook. Each response has numbered citations, quoted source passages, and a "Locate in PDF" option.
It answered all nine of our test questions correctly. The full Federal Reserve report uploaded on the free plan, and SciSpace returned the correct $30,070 billion Treasury figure. It also recognized when information was missing, catching both the blank rent field and the federal funds forecast the report never gives. Scanned pages posed no problem either, since the 1915 textile journal read cleanly on the free plan.
There were a couple of issues. One answer about freight charges came back with broken LaTeX formatting, making the $12 and $4 figures hard to read. SciSpace also treats nearly every upload like an academic paper, so even a room rental agreement may get longer, research-style responses.
Key Features
- Numbered citations with quoted source passages
- OCR support for scanned PDFs
- Math and table explanations
- Highlight-to-chat and Save to Notebook
- Support for 75+ languages
Free Limits & Pricing
The free Basic plan includes 100 monthly credits. Premium costs $12/month billed annually and gives you 1,200 credits.
4. Adobe Acrobat AI Assistant
Adobe Acrobat AI Assistant works right inside Acrobat, so you never leave the reader to ask a question. Answers come with numbered citations and an "Uploaded sources" panel that shows the passages behind each one.
Acrobat performed well across our tests, finding the $30,070 billion Treasury figure in the Federal Reserve report and identifying the 30-day notice rule in the rental agreement. It also recognized when the requested information wasn’t in the file and successfully read the scanned 1915 textile journal. Its answers run a little long, though, with extra explanation even when a shorter response would work.
The free preview lasted six answers in our testing before the subscription wall took over - Adobe doesn't publish the exact allowance.
Key Features
- Built into the Acrobat reader alongside its editing and e-sign tools
- Numbered citations backed by a quoted-sources panel
- Document-aware suggested prompts
- Scanned file support
Free Limits & Pricing
PDFs can be up to 100 MB or 600 pages, with questions capped at 500 characters. AI Assistant Plus costs $4.79/month on the annual plan.
5. Humata AI
Humata feels built for research-heavy work. It accepts PDFs, Word files, spreadsheets, slide decks, web links, and YouTube videos, then answers with bracketed citations and page references. It can also suggest follow-up tasks, such as drafting a briefing note or checking a document for specific requirements.
The free plan was restrictive in our test. The 71-page Federal Reserve report exceeded the 60-page limit, so we had to shorten it first. Our scanned 1915 journal couldn’t be tested at all because OCR is only available on the $49 Team plan.
For files it could process, Humata performed well. It found the 30-day notice rule in the rental agreement, correctly said the rent field was blank, and returned the $30,070 billion Treasury figure with a list of supporting page references. It also refused to invent a forecast that wasn’t in the report.
Key Features
- Bracketed citations with page references
- Support for PDF, DOCX, PPTX, XLSX, CSV, web pages, and YouTube
- Fast, Visual, and Thinking response modes
- Suggested document tasks
- Folder permissions on business plans
Free Limits & Pricing
The free plan includes 60 pages and 10 answers, with no OCR. Paid plans start at $1.99/month.
6. AskYourPDF
AskYourPDF has plenty of extras. A model picker lets you choose from OpenAI, Google, and Anthropic, and the platform adds podcast conversion, multi-document chats, and support for many languages. Answers are well organized, with headings, numbered citations, and quoted text from the PDF.
It handled regular text PDFs well. AskYourPDF found the 30-day notice clause in our rental agreement and correctly noted that the rent field was blank. But it struggled with harder files. When we asked for a value from Table 1.1 of the Federal Reserve report, it couldn’t find the number even though it appeared in the document. The scanned 1915 textile journal was another miss.
AskYourPDF didn’t read the image-based pages and instead asked us to describe them. One response also included a link promoting the company’s own summarizer.
Key Features
- Model picker with GPT-5.2 and Gemini 2.5 Flash
- Podcast conversion and multi-document chats
- Numbered citations with quoted source text
- Developer API and browser extension
Free Limits & Pricing
The free plan includes 1 document per day, up to 100 pages or 15 MB, plus 50 questions and 3 conversations. Premium costs $11.99/month billed annually, while Pro costs $14.99/month. A $1 trial is available.
7. Smallpdf Chat with PDF
Smallpdf was the fastest platform in our tests. It works alongside the company’s compression, conversion, editing, and signing tools, and you can start without creating an account. Each answer has page-number links and suggested follow-up questions.
The speed came with a serious accuracy problem. When we asked what the Federal Reserve report forecasts for the federal funds rate at the end of 2026, Smallpdf answered 5.25%. The report doesn’t provide that forecast. Other platforms correctly said the information wasn’t there, while Smallpdf supplied a number and attached page references to the response.
It handled simpler questions correctly, including the $30,070 billion Treasury figure, the 30-day notice rule in our rental agreement, and the blank rent field. Scanned PDFs were another limitation. Our 1915 textile journal was rejected because the file contained no readable text layer.
Key Features
- Part of the Smallpdf PDF toolkit
- No account required to start
- Page references with suggested follow-up questions
- Fast responses for text-based PDFs
Free Limits & Pricing
The free plan supports 25,000-35,000 words per document. Pro costs $9/month billed annually and raises the limit to 100,000 words.
How to Choose the Best Tool to Chat with PDF
The best choice depends on the files you work with, how often you use PDF chat, and how easily you want to verify each answer.
Check Scanned PDF Support
Scanned contracts, old records, and image-only PDFs need OCR before a chat tool can read them.
FormsPal, ChatPDF, SciSpace, and Adobe Acrobat handled our scanned 1915 journal on free plans. Humata and AskYourPDF reserve OCR for paid users, while Smallpdf rejected the scan entirely.
See How Citations Work
Citations aren’t equally useful. A page number helps, but direct source text saves more time.
FormsPal highlights the exact sentence behind an answer, while SciSpace shows the quoted passage with a "Locate in PDF" option.
Smallpdf tends to link several pages without pointing to the line that supports the answer.
Ask About Something That Isn’t There
A good PDF chat should know when the document doesn’t contain an answer. When we asked about a federal funds forecast missing from the Fed report, most platforms said it wasn’t provided. But smallpdf instead returned 5.25% and added page references, making the incorrect answer look supported.
Check Free Plan Limits
Free access varies sharply. For example, ChatPDF allows two chats per day, AskYourPDF one document daily, Humata 60 pages and 10 answers, and FormsPal 10 questions per document across five files a day.
So, pick a limit that matches how often you expect to use the service.
Review File Privacy
Privacy matters when PDFs contain contracts, financial records, or client information. Check how long uploads stay on the server, whether files are stored after your session, and whether document content can be used for model training.
What Is the Best Free Tool to Chat with PDF?
FormsPal PDF Chat handled our test set better than anything else we tried. Text-based files and scans both work, every answer traces back to the source text, and the tool tells you plainly when the document doesn't hold the information you asked for. The free plan gives you 10 questions per document and up to 5 documents a day, enough room for regular use without paying right away. You can also start without creating an account, and scanned PDFs don't require a separate OCR subscription.
Try FormsPal PDF Chat on a document you're working on now. It's free, needs no account, and shows you the sentence behind every answer.
FAQs
What is the best PDF chat tool for summarizing documents?
FormsPal produced the strongest summaries in our testing, each one backed by page citations you can click. ChatPDF came close and can turn a summary into flashcards or slides, which suits study material. For long reports with equations and tables, SciSpace breaks documents down into sections.
Can AI chat with PDF handle scanned documents?
A scan has no text layer, so the platform needs OCR to read anything. FormsPal, ChatPDF, SciSpace, and Adobe Acrobat read our scanned pages on free plans. Humata and AskYourPDF reserve OCR for paid tiers, and Smallpdf rejected the file outright.
How accurate is PDF AI chat?
Accurate enough to save time, not accurate enough to skip verification. Most tools returned correct figures from tables and contract clauses in our testing. One produced a number that appeared nowhere in the document. Click the citation before acting on anything that matters.
What happens to files uploaded to a chat PDF AI online tool?
Retention policies vary. FormsPal deletes documents after the session and never uses them for model training. Smallpdf deletes uploads after one hour, unless you choose to save them to your account. Other services may follow different retention rules, so check the privacy policy before uploading confidential or client documents.
What is the best tool to chat with PDF reports over 100 pages?
Check page caps first. For example, Humata's free plan limits you to 60 pages. SciSpace and FormsPal accept the full file. AskYourPDF caps free uploads at 100 pages, and paid plans go up to 2,500 or 6,000 pages.