Does Your PDF Need OCR? The 10-Second Test
The 10-second test: open the PDF and try to select text with your mouse. If you can select and copy it, no OCR needed. If you can’t select anything (or selection grabs whole pages as images), the PDF is scanned images and needs OCR.
Not every PDF needs OCR — running it on PDFs that already contain text wastes time and can even degrade quality. This guide shows how to tell in seconds, plus what to do in each case.
The 10-Second Test
Try selecting text
Open the PDF, drag your mouse across a paragraph. Text highlights cleanly? It’s a real text PDF — no OCR needed.
Try Ctrl+F
Search for a word you can see on the page. Found? The PDF has a text layer. Not found? It’s scanned images.
Check the file properties
In your PDF reader, check document properties or try “Save as text”. Scanned PDFs are suspiciously large for their page count (full-page images) and export as blank.
What to Do in Each Case
✅ Text selects fine → no OCR needed
Your PDF is already searchable. If text looks garbled when copied (common with some generators), that’s a font-encoding issue, not an OCR problem — try “Print to PDF” to normalize it.
❌ Nothing selects → needs OCR
It’s a scanned-image PDF. Run it through our searchable-PDF workflow — free, keeps the original appearance, adds the invisible text layer.
⚠️ Some pages select, some don’t → mixed PDF
Common with merged documents. OCR only the scanned pages (or the whole file — harmless), then export. gImageReader’s batch queue handles mixed stacks easily.
Frequently Asked Questions
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