Work with scanned PDFs using local OCR
A scanned PDF may contain pictures of text rather than text you can select. Optical character recognition helps interpret those pictures, but recognition and redaction are different tasks.
Two distinct workflows
Make PDF searchable is a Pro and Enterprise utility. It recognizes printed English pages and exports a PDF with page images and selectable text. It preserves the visible information; it does not redact it.
Batch identifier redaction checks rendered printed English content as well as native text for selected patterns. Its output is a new page-image PDF with matched regions covered and no searchable source text layer.
Recognition runs on your device
The app serves its OCR worker, engine and English language data from its own assets. Recognition runs locally, without sending scanned pages to an external OCR service. The browser must first load those assets; there is no guarantee a fresh browser visit will work offline.
Prepare a useful scan
Use readable, upright pages with adequate contrast. Test faint print, rotated text, dense tables and unusually large pages before processing a batch. The renderer bounds resolution to control memory, so tiny characters can be difficult to recognize.
Review mistakes and omissions
Handwriting and other languages are not supported claims for the bundled English workflow. A missed digit can prevent an identifier match. Compare output against the source and inspect every page before sharing.