How to tell if a PDF is scanned (quick tests)
You don’t need special software. These tests work in most PDF viewers.
Test #1 (10 seconds): Try selecting ONE word
If you can’t select individual words/letters and it highlights like an image, your PDF is scanned (image-only).
Test #2 (10 seconds): Ctrl+F a word you can see
Search for a unique word (e.g., a name or invoice number). If nothing is found, there’s likely no searchable text layer.
Test #3 (10 seconds): Zoom to 300–400%
If letters become pixelated like a photo, it’s likely scanned. Real text usually stays crisp when zooming.
Test #4: Check another page (mixed PDFs are common)
If some pages search and others don’t, the file is mixed: some pages contain text, others are scanned images.
Most reliable signal
If you can’t select a single word, your PDF is almost certainly scanned (image-only). OCR is the fix.
Why PDFs become “image-only” (and what to do)
Cause A: The PDF came from a scanner or phone camera (most common)
What you’ll notice
- It’s a photo/scan of the page
- No underlying text exists in the file
- Search/copy/highlight won’t behave like normal text PDFs
Fix: Run OCR to add an invisible text layer
OCR (Optical Character Recognition) detects letters in the scanned image and creates a searchable text layer underneath. The PDF looks the same, but becomes searchable and selectable.
Cause B: It’s partially scanned (mixed content)
What you’ll notice
- Some pages were generated digitally (search works)
- Some pages are images (search fails)
- Common in merged PDFs, email attachments, or “print-to-PDF” + scan workflows
Fix: Split and OCR only the scanned pages
Splitting saves time and improves control—OCR the pages that need it, keep text pages untouched.
Cause C: Search fails due to a broken/odd text layer
What you’ll notice
- Text exists but search doesn’t match reliably
- Copy/paste output is weird or inconsistent
- Some PDFs use unusual encoding or embedded fonts
Fix: OCR often rebuilds a cleaner searchable layer
If you need reliable search across the whole document, OCR can normalize output. If you only need the words, extract text instead.
What OCR changes (and what it doesn’t)
In most cases, your scanned page image stays the same — OCR simply adds an invisible searchable text layer underneath so Ctrl+F, selection, and copy work.
If you want editing (not just search), OCR first then convert: Scanned PDF to Word (OCR) or Scanned PDF to Excel (OCR).
Best next step (pick your goal)
The fastest workflow depends on what you’re trying to do.
FAQs
How can I tell if a PDF is scanned?
Try selecting a single word. If you can’t highlight individual words/letters and the page behaves like an image, it’s likely a scanned (image-only) PDF.
Why doesn’t Ctrl+F work on a scanned PDF?
Because scanned PDFs often contain only image data (a picture of the page), not real text. Ctrl+F can only search actual text until OCR creates a text layer.
What does OCR do to a scanned PDF?
OCR detects letters in the image and adds an invisible text layer underneath, making the PDF searchable, selectable, and easier to copy from.
Can a PDF be partially scanned?
Yes. Mixed PDFs are common—some pages contain real text, others are scanned images. OCR the scanned pages for consistent search results.
My PDF is too long and there’s a page limit. What should I do?
Split the PDF into smaller parts, keep only the pages you need, then run OCR on that smaller file.
Convert your scanned PDF into a searchable PDF
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