How to make a scanned PDF searchable
By PDFEditor.ae · Published
What makes a scan searchable
A searchable scan keeps the page images and adds an invisible layer of recognised text behind them, produced by OCR (optical character recognition). You can then search and select words, while the page still looks like the original.
Where to run OCR
PDFEditor.ae does not offer OCR at the moment. Many desktop PDF editors, office suites and phone scanning apps include it. Choose one that supports the language of your document — recognition of mixed or right-to-left scripts varies a lot between tools.
Steps
- Check the scan is sharp and straight; OCR cannot read what you cannot.
- Run OCR on a copy, with the document's language selected.
- Save the searchable PDF.
- Search for several terms you know appear on different pages, including a name and a reference number near the end.
A mistake to avoid
The hidden text can contain errors even when the page looks perfect. If a search fails, look at that page: it may be a recognition mistake rather than a missing page. Never copy figures out of OCR text without checking them.
What you can do with a scan here
Without OCR, you can still merge, split, rotate, sign, fill and annotate scanned PDFs on this site, and turn phone photos into a PDF.