How to Make a Scanned PDF Searchable (Free OCR)
A scanned PDF is just pictures of pages — you can't search it, select text or copy a paragraph. OCR (optical character recognition) fixes that by reading the images and embedding an invisible text layer behind them, and it can run entirely in your browser.
Last updated: July 2026
To make a scanned PDF searchable, run OCR on its pages and embed the recognized words as an invisible text layer aligned with the scan. The free PDF Editor here does this locally: open the PDF, click OCR, then download — the result looks identical but becomes selectable and searchable. Nothing is uploaded.
Edit a PDF online free — add text, whiteout, highlights, pen drawings, checkmarks and images, then run OCR to make scans searchable. 100% private, no upload.
Step by step
- Open the free PDF Editor and choose your scanned PDF.
- Click “OCR — extract text” and let it read each page.
- Copy the extracted text if that's all you need — or keep the invisible-text-layer option ticked.
- Download the PDF: it now supports search, text selection and copy-paste.
How a searchable scan works
OCR software recognizes each word in the page image along with its exact position. Those words are then written into the PDF as transparent text placed precisely over the printed words. Viewers show the original scan, but search, selection and screen readers use the hidden layer underneath — the standard technique used by professional scanning software.
What affects OCR accuracy?
Resolution and contrast matter most: clean 300-DPI scans of printed text recognize very well; phone photos at an angle, low light or handwriting reduce accuracy. If a page reads poorly, re-scan it flat and well-lit rather than fighting the output.
Privacy: why local OCR matters
Scanned documents are usually the sensitive ones — contracts, records, IDs. Running OCR in your browser (via WebAssembly) means the pages are never transmitted to a server, which is a real difference from most online OCR services.
FAQ
Does OCR change how the PDF looks?
No — the scan stays pixel-identical. The recognized text is embedded invisibly behind the image.
Which languages are supported?
English works out of the box; recognition quality is best on clean printed text.
Is my document uploaded for OCR?
No — the OCR engine runs in your browser via WebAssembly. The document never leaves your device.
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