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OCR a PDF: Make a Scanned PDF Searchable Without Uploading

June 4, 2026 · 2 min read

A scanned PDF is really just a picture of a page. You can see the words, but you can't select, search or copy them — because to the computer they're pixels, not text. OCR (optical character recognition) fixes that by reading the image and recovering the actual characters. This guide explains how OCR works and how to run it in your browser, so a scanned document stays on your device.

What OCR does

OCR analyses the image of a page, recognises letter shapes, and reconstructs the text. After OCR you can:

  • Search the document for a word or number.
  • Select and copy text out of it.
  • Feed it into a PDF-to-Word or PDF-to-text conversion that actually contains words.

It's what turns a stack of scans into usable, searchable documents.

Why run OCR locally instead of uploading

Scanned documents are often the most sensitive things people own: contracts, IDs, tax forms, old letters, medical paperwork. Cloud OCR services require uploading all of that. Running OCR in the browser keeps the scan on your device — the recognition happens locally using a WebAssembly build of the open-source Tesseract engine.

To confirm it: open DevTools → Network and run OCR. You won't see the file being uploaded.

How to OCR a PDF in your browser

  1. Open the OCR PDF tool.
  2. Add your scanned PDF.
  3. Let it process — recognition runs on your device, so speed depends on your machine and the number of pages.
  4. Use the recognised text, or export it.

Tips for the best results

  • Higher-quality scans win. 300 DPI, straight (not skewed), high-contrast pages OCR far more accurately than low-resolution phone photos.
  • Clean originals matter. Coffee stains, handwriting over print, and faint photocopies all reduce accuracy.
  • Set expectations. OCR is excellent but not perfect — proofread important numbers (dates, totals, IDs) after recognition.
  • Heavy job, be patient. OCR is computationally intensive; large documents take longer because the work happens on your device rather than a data center.

After OCR

Once your scan is searchable, you might want to convert it to Word for editing, extract the plain text, or redact sensitive details now that they're recognisable.

The bottom line

OCR makes a scanned PDF genuinely useful — searchable, selectable, convertible — and there's no reason to upload private scans to do it. Run OCR on your PDF entirely in your browser.