What is Searchable PDF?
A PDF that contains an invisible text layer behind the scanned image, making the document searchable and selectable.
A searchable PDF (sometimes called a 'sandwich PDF') is produced when OCR runs over a scanned document and the recognized text is embedded as an invisible layer aligned with the original image. The visual look is unchanged, but users can now Ctrl+F, copy text, and feed the file into downstream automation.
Also known as
- sandwich PDF
- text-layer PDF
Related terms
- OCR (Optical Character Recognition) — OCR is the technology that converts text inside an image or scanned PDF into machine-readable, searchable, editable text.
- Image-Based PDF — A PDF whose pages are scanned images with no underlying text layer — meaning text cannot be searched or selected.
- Tagged PDF — A tagged PDF carries a hidden structure tree (headings, paragraphs, lists, tables) that screen readers and automation tools use to understand reading order.
Category: PDF Format