Free PDF AI detector for any document
Upload a PDF and find out how likely it is that AI wrote it. Free, private, and nothing you upload is kept.
Check your textHow to read your AI detector score
The AI detector gives you a single number from 0 to 100. It is the estimated chance that AI wrote the text, not a yes or no. Here is what each band means.
Probably a person
Reads like human writing. We did not pick up the patterns a model tends to leave behind.
Hard to say
Some of it leans one way, some the other. Read it yourself before you draw a conclusion.
Probably AI
This has the marks of machine-written text. Read it closely before you conclude anything.
How the PDF AI detector works
Three steps, a few seconds, no setup.
Add your text
Paste it, upload a Word or PDF file, or drop in a link to the page you want to check.
We check the patterns
We pull the text out of your PDF, then weigh it against the patterns of AI writing and human writing.
Read the score
You get a number from 0 to 100 and a plain read on how likely AI was involved.
Check a PDF without copying and pasting
Switch to the Upload tab and choose your PDF. We extract the text, score it, and show a result in seconds, so you do not have to select and paste page by page. It works on essays, research papers, reports and any other text-based PDF.
Scanned PDFs and images
One catch: a PDF made from scans or photos has no text layer to read, so there is nothing for the detector to score. If your PDF is a picture of a page rather than selectable text, run it through OCR first, or paste the text in directly.
Headers, footers and references
PDFs from journals and reports often carry page headers, footers, and a bibliography that repeat across pages. We pull all of that out with the body text. Repeated page furniture and a citation list rarely look AI-written, so they push the average toward human. If you want a clean read on just the prose, paste the body sections in instead of uploading.
Tables and figure captions
A PDF's text extractor reads tables and captions in reading order, which is not always the order you would skim them in. The detector still scores the prose around them fine, but table-heavy pages can read as fragmented and land in the unclear band. Use that as a hint to focus on the surrounding paragraphs.
Where your PDF goes
We open your PDF in memory, pull out the text, and score it. The file and the extracted text are dropped the moment you have a result.
Nothing is logged, stored, or used to train anything.
PDF AI detector FAQ
Is the PDF AI detector free?
Yes. Upload as many PDFs as you like, with no account.
How big a PDF can I upload?
Up to 10 MB. We read the text, not the images, so most documents fit easily.
Why did my PDF return no text?
It's probably a scan or image with no text layer. Run OCR first, or paste the text in.
Do you keep my PDF?
No. The file and its text are dropped as soon as you get a score.
Can I check a Word file too?
Yes. The Word AI detector handles .docx files the same way.