Is my PDF scanned?
Drop a PDF to see whether its pages have real text or are only pictures of pages. It runs in your browser, and nothing is uploaded.
How the check works
A PDF can hold two things on a page: text, which your reader can search and select, and images. A scanner or phone app saves each page as an image. Unless OCR has been run, there is no text behind it.
- Your PDF is opened in this tab. The page loads pdf.js, Mozilla’s open-source PDF reader, and reads the file from your disk. No copy is sent anywhere.
- Every page is asked for its text. A page counts as having text when it holds at least 25 letters or digits. That ignores a stray page number or a short library stamp.
- Pages with text are looked at once more. OCR hides its text behind the page image by making it invisible. If up to 40 sampled pages show invisible text, the PDF is a scan that has already been through OCR.
You get one of three answers. Scanned (images only): no page has text. Has text: every page has text. Mixed: some do and some don’t, with the page numbers that don’t.
A scan that already has text can still be hard to read on an e-reader: grey paper, wide margins, a huge file. If yours is, see how to clean up a scanned PDF, or check it against device limits with will my PDF fit?
Questions
How can I tell if a PDF is scanned without a tool?
Open it and try to select one word, or search for a word you can see on the page. If nothing highlights and search finds nothing, that page is a picture with no text behind it.
What does “mixed” mean?
Some pages have text and some are only pictures. Common causes: a digital cover or title page in front of a scanned book, or OCR that skipped or failed on some pages.
My PDF “has text”, but search still misses words. Why?
This check sees whether text is there, not whether it is right. OCR on a faint or grey scan can produce misspelt or garbled text. Cleaning the pages first and reading them again usually helps.
Is my file uploaded anywhere?
No. The check runs in your browser with pdf.js, Mozilla’s open-source PDF library. Your PDF is read on your own computer and never sent to us.
Why does it matter on an e-reader?
Without a text layer you cannot search, highlight, copy or look up a word, and Send to Kindle’s conversion has no text to work with. A scanned page is also shown at its full size, margins included, so text is small.
How do I make a scanned PDF searchable?
Run it through OCR, which reads each page and adds hidden text under the image. Our guide to making a scanned PDF searchable compares the ways to do it.
Does it work on large books?
Yes, but it reads every page, so a long book takes longer, and a very large file needs enough memory on your device. Password-protected PDFs cannot be checked.