Run OCR on a scanned PDF

How to Run OCR on a PDF

1

Add your scanned PDF

Click “Select file” or drag and drop a scanned or image-based PDF. Heavily scanned files (50+ pages) take longer to process.

2

Choose a language

Pick the primary language of the document — English, Spanish, French, German, Hindi, or 100+ others. Better language match = better recognition accuracy.

3

Run OCR and download

Click “Run OCR”. Tesseract loads in your browser on first use (~10MB, then cached). The output is a new PDF with a searchable text layer over the original scans.

Every step runs in your browser. No server uploads, no waiting.

Why use this tool

DukPdf’s OCR PDF tool adds a searchable text layer to scanned PDFs and image-based documents. The OCR engine runs entirely in your browser using Tesseract.js — recognized text is embedded in the PDF so you can search, select, and copy it. Your scanned documents never leave your device. To compress the OCR’d result, use Compress PDF. To merge with other PDFs, use Merge PDF. For a step-by-step guide, see our OCR PDF guide.

When you'd use this

Digitize old archives

Make scanned books, magazines, and historical documents searchable so you can Ctrl+F across decades of content.

Searchable receipts

OCR a stack of scanned receipts so you can search by vendor, date, or amount — no more scrolling through images.

Legal discovery

Make scanned evidence searchable. Find specific terms across thousands of pages of PDF scans without re-typing the document.

Accessibility

Add a text layer to scanned documents so screen readers can read them aloud to users with visual impairments.

Why this matters for your privacy

☁️ CLOUD PDF TOOLS
📄 your-file.pdf
↓ uploaded over the internet
☁️ their server

A copy of your document sits on someone else’s infrastructure — deleted on their schedule, not yours.

✗ OUT OF YOUR HANDS
DukPdf
📄 your-file.pdf
⟳ stays right where it is
💻 your device

Processed by your own browser, start to finish — on your machine, under your control.

✓ STAYS ON YOUR DEVICE

We send the software to your file — not your file to our servers.

OCR PDF — questions

What languages are supported?

100+ languages including English, Spanish, French, German, Italian, Portuguese, Hindi, Arabic, Chinese, Japanese, Korean, and many more. Pick the primary language of the document for best accuracy.

How accurate is the OCR?

Tesseract achieves 95%+ accuracy on clean, high-resolution scans. Accuracy drops with low resolution, skewed pages, or unusual fonts. For best results: scan at 300 DPI, ensure pages are straight, and avoid handwritten content.

Can OCR handle handwritten text?

Limited. Tesseract is optimized for printed text. Handwriting recognition works for very clean block letters but struggles with cursive, stylized, or messy writing. For handwritten documents, accuracy is significantly lower.

Is my PDF uploaded during OCR?

No. OCR runs entirely in your browser using Tesseract.js. Your scanned document never leaves your device. Open DevTools → Network tab — zero upload requests.

How long does OCR take?

Roughly 2–5 seconds per page on a modern device. A 50-page document takes 2–4 minutes. Processing is local, so faster hardware finishes faster.

Does the original scan stay unchanged?

Yes. The output is a new PDF with a text layer added on top of the original scans. Visually identical to the input, but now searchable and selectable.

Tools that pair with ocr pdf

→ Compress PDFShrink the OCR’d result→ Merge PDFCombine with other PDFs→ Edit MetadataSet title and author→ Extract PagesOCR only specific pages→ JPG to PDFConvert image scans first→ Rotate PDFRotate sideways scans first
🔒 DukPdf — YOUR FILES NEVER LEAVE YOUR DEVICE

Ready to run ocr on a pdf? Your files stay yours.

No server uploads. No watermark. Just open a tool, drop your files, and download the result. Your original files are never modified.

↑ Back to upload