The difference between a "text" PDF and a "scanned" PDF
A PDF exported from Word, Google Docs, or a website contains real, selectable text — you can highlight and copy it directly. A scanned document, on the other hand, is really just a photograph of a page saved as a PDF. To a computer, it's a picture, not words — which is why you can't select or search text inside it.
What OCR does
OCR (Optical Character Recognition) analyses the shapes in a scanned image and recognises them as letters and words, effectively converting a picture of text into actual, usable text. It's the technology that turns a stack of paper scans into something you can search, copy, and edit.
Common situations where you need OCR
- Old documents that only exist as physical paper, now scanned
- Photos of receipts, forms, or printed pages taken on a phone
- PDFs received from someone else that turn out to be scans, not real text
How accurate is OCR?
Modern OCR is quite reliable on clear, well-lit scans of standard printed text — accuracy is typically very high for clean documents. Accuracy drops with low-resolution scans, unusual fonts, handwriting, or documents with heavy background noise (stamps, watermarks, coffee stains). For a quick way to check quality, compare a paragraph of the OCR output against the original scan.
Extract text from your scan
The PDFGuy OCR PDF tool runs recognition entirely on your device — no upload, no account — and gives you copyable, downloadable text from a scanned PDF.