OCR Text Layer
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Definition
Section titled “Definition”OCR (optical character recognition) converts the shapes of letters in an image into real text. An OCR text layer is the result placed invisibly over a scanned page: the reader still sees the original image, but behind it sits a text layer that can be searched, selected, copied, and read aloud. A scan without a text layer is a photograph of a document; a scan with one is a document.
Example
Section titled “Example”A scanned 30-page contract. Before OCR, searching for a clause name returns nothing and the pages cannot be selected. After OCR adds the text layer, the same file can be searched page by page, the text can be copied into another document, and keyword splitting can find section boundaries — all while the page still looks exactly like the scan.
In the PDFLean tools
Section titled “In the PDFLean tools”- OCR a PDF — adds a text layer to a scan, on-device, free, no upload
- make a PDF searchable — the guide for the single-file case
Related reading
Section titled “Related reading”- Raster and Vector — why a scan has no text to select in the first place
- PDF/A — where the text layer matters for archival quality
- Build a Searchable Archive — the whole-archive version of the same job