What Is PDF OCR?
PDF OCR (Optical Character Recognition) converts scanned PDFs and image-based documents into searchable, selectable text. If you have a PDF from a scanner, fax, or photograph that you can’t copy text from, this tool makes it readable and searchable.
How to Use This Tool
Upload a scanned or image-based PDF and select your preferred language. The OCR engine processes each page, detecting and extracting text from the images. Once complete, download the new searchable PDF where you can highlight, copy, and search text. All processing happens in your browser.
Why Use PDF OCR?
Professional OCR software can be expensive and often requires uploading documents to cloud services. This tool runs OCR entirely in-browser, so sensitive scanned documents like medical records, legal filings, and financial statements stay on your device. For a detailed walkthrough, see our step-by-step guide.
See also: The PDF Text Extractor pulls only the embedded text layer; for scanned PDFs without one, run OCR first. The Image OCR extracts text from photos and screenshots (PNG/JPG) rather than only PDFs.
Worked example: how accurate it is on scanned pages
On October 13, 2026 we rendered one page of English text (a 506-character meeting note with names, dates, times and numbers) as image-only PDFs in four scan conditions, ran each through this tool in Chromium (tesseract.js 5.1.0, English) and compared the text with the original, character by character (edit distance; script: _ops/checks/pdf-ocr/).
| Scan | Character accuracy | Time |
|---|---|---|
| Clean scan, 300 dpi, 11 pt serif | 100.0% | 5 s |
| Clean scan, 150 dpi | 100.0% | 6 s |
| Typewriter-style monospace, 200 dpi, blurred, speckled, tilted 0.8° | 100.0% | 5 s |
| Faded photocopy: grey text on grey paper, 200 dpi, blurred | Unreadable (output was mostly invented characters) | 55 s |
- Clean printed text is read exactly, even at 150 dpi, and so was moderate blur, speckle and a slight tilt.
- Contrast is what breaks it. The faded photocopy, with grey text on grey paper, came back as nonsense rather than as text with a few errors. Raise the contrast (or rescan darker) before running OCR; for a single page, the Image OCR tool can also upscale and invert the image before reading it.
- These are our pages, not a guarantee. Real scans add skew, columns, tables, stamps and handwriting; Tesseract does not read handwriting reliably. Proof-read anything you will rely on.
Sources
Checked on .
Frequently Asked Questions
Built by Derek Giordano · Part of Ultimate Design Tools
Tesseract.js runs the OCR locally in your browser, with language models loaded on demand from your chosen pack — English, Spanish, German, French, Portuguese, Dutch, Italian, Russian, Chinese Simplified, Japanese, Korean, and Arabic. The result is a searchable PDF with an invisible text layer over the original page image, so the document looks identical but Cmd-F now works. Scanned receipts, old contracts, and book chapters become greppable without paying for Acrobat Pro.