ChatPDF alternative: who to pick, and where UniqAI loses

Two reasons come up again and again.

The free plan runs out. ChatPDF's own home page says the free plan covers 2 documents a day. That is fine for a one-off question. It is tight if you read papers, contracts or reports every day.

One more subscription, only for PDFs. A single-purpose tool is easy to understand, but it is one more monthly bill next to the chat assistant, image tool or editor you already pay for. Some people would rather ask their PDF questions inside something they already use.

If neither bothers you, ChatPDF may be the right pick. The rest of this page is a fair look at who should choose what. UniqAI is one of the options, and it loses on some points, which we say plainly below.

Start with the job, not the brand.

• ChatPDF if you want one simple, single-purpose PDF chat and nothing else. It does that one thing, and the free plan lets you try it.
• Claude or NotebookLM if your files are very large or you have many sources. Their limits in the table are far above our 5.7 MB. If you are reading a thick report or a stack of papers, they are the better fit than UniqAI.
• Adobe Acrobat if you edit and sign PDFs all day and already pay Adobe. The AI Assistant is part of Acrobat Studio, so the question is whether the whole suite suits your work.
• Smallpdf if you want a full PDF editing suite. Its chat is one tool among many, with a free daily allowance.
• UniqAI if you want PDF actions inside a subscription you already use for chat, images and video. You also choose the model: GPT-4o mini, Claude Haiku 4.5, Claude Sonnet 4.6, Gemini 2.5 Pro, GPT-5 and more. Merge and split run free in your browser, so those pages never leave your device.

The table has gaps because vendors do not always publish a figure. Check the vendor's page before you pay.

Three places, and they matter.

No OCR. The tool reads the text layer of a PDF. A scan or a photo of a page gives no usable text, and the model is told to say so. If most of your files are scans, pick something else.

Smaller files. About 5.7 MB per PDF, and up to 4 files per message. Claude and NotebookLM accept far more, as the table shows.

Compare needs a paid plan. Comparing two PDFs takes exactly two files and a paid plan, because the free plan's input cap is too small for two documents.

The free plan also reads about 8,000 input tokens a message, so a long document may be cut. Paid plans read more. We would rather you know that before you sign up.

Run the same short test on every tool you are considering. Take one real PDF, the kind you read most often, and write down three questions you already know the answers to.

• One lookup. A figure or a date that sits in one place.
• One sum. A total that needs several lines added up. Models slip here more than on lookups, as our test of three models showed.
• One thing the file does not say. Ask about something the document is silent on. A good tool says the document does not cover it. A weak one invents an answer.

Then compare the replies. Did the tool quote the page? Did it say when it was unsure? Did it read the whole file, or stop part way? And what does its limits page say about a file the size of yours?

A tool that fails the test on your own file is the wrong tool, whatever its price. For habits that make any answer easier to check, see how to chat with a PDF.

These readers are fictional. They show how the table turns into a decision.

• Priya asks a one-off question about a short paper now and then. Her files are small and text based. She starts with the daily allowances in the table and pays nobody until she hits one.
• Marco receives scanned supplier invoices. UniqAI would not suit him, because it has no OCR and a scan gives no usable text. He tries one scan in each of the other tools before paying for any of them.
• Lena works from a very thick annual report that is far larger than 5.7 MB. The limits in the table point her to Claude or NotebookLM, which accept much bigger files.

None of them picked the cheapest tool. Each picked the one whose limit did not get in the way of the files they actually have.

Four come up often.

• Judging by price alone. The table has gaps, so a missing price is not a low price. Open the vendor's page and read the figure on the day you buy.
• Ignoring where the file goes. A PDF chat sends the file's text to a provider. Read the privacy page of each tool before you add contracts, medical records or anything private.
• Moving everything at once. Keep the old tool for a week and run both on the same questions. Cancel when the new one has handled a real task.
• Skipping the page check. Whichever tool you pick, a model can state a wrong fact in a confident tone. Ask for the quoted sentence and find it on the page.

A switch that costs you an afternoon of testing is cheap. A switch that you regret in the middle of a deadline is not.

A message costs Gems, and you see the cost before you send it. The fast tier is 1 Gem a message (GPT-4o mini, Gemini 2.5 Flash Lite, DeepSeek V4 Flash). The smart tier is 5 Gems (Claude Haiku 4.5, GPT-5, Claude Sonnet 4.6, Gemini 2.5 Pro, Grok 4.3). One message costs the same no matter how many files you attach. New accounts start with 30 Gems. See pricing for plans and Gem packs.

Which model should you pick for a PDF? We ran a small test on three PDFs and nine questions. The results are in the best AI model for reading PDFs, including where the cheaper model slipped.

Every answer has Copy and "Download .md" buttons, so you can take the reply with you. The PDF goes to the model provider you picked, and is sent again with each message.