PDFresh guide
PDF Text Layer vs OCR: What Is the Difference?
Learn the difference between a PDF text layer and OCR, and when PDFresh text extraction can or cannot help.
Text layer
A PDF with a text layer contains selectable characters behind or alongside the visible page. Text extraction can read that existing layer.
OCR
OCR analyzes page images and creates text from the shapes of letters. It is needed for many scanned image-only PDFs.
Where PDFresh fits
Extract PDF Text reads existing embedded text in your browser. It does not create new text from scanned images.
When to use OCR
Use an OCR tool when a scan looks like text but PDFresh returns little or no selectable text.