Advanced PDF OCR - Extract Text Securely

Convert scanned PDFs into searchable documents. Accurately extract text while keeping everything 100% private and offline in your browser.

How it works:

  • Extract Text: Uses Tesseract OCR to recognize text from scanned images or PDFs.
  • Searchable Output: Creates a new PDF with an invisible text layer, making your document fully searchable while preserving the original appearance.
  • Character Filtering: Use whitelists to filter out unwanted characters and improve accuracy for specific document types (invoices, forms, etc.).
  • Multi-language Support: Select multiple languages for documents containing mixed language content.

Click to select a file or drag and drop

Your files never leave your device.

How to OCR PDF Online

1

Upload Document

Select your scanned PDF. The file is processed locally, ensuring total privacy.

2

Configure Settings

Select the languages in your document, adjust the resolution, or pick a character whitelist for better accuracy.

3

Extract & Download

Click 'Start OCR' to generate a searchable PDF or plain text file instantly.

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Frequently Asked Questions

Is this OCR tool completely free?

Yes! Our OCR PDF tool is completely free to use with no limits on file size or the number of pages.

Are my scanned documents private?

Absolutely. ZentoPDF uses WebAssembly, which means the OCR engine runs entirely in your local browser. Your documents are never uploaded to any server.

Can I recognize multiple languages at once?

Yes, you can select multiple languages from the list to recognize text in documents containing multiple languages.

What is the character whitelist preset?

A whitelist limits the characters the OCR will try to recognize. For example, if you know a document only contains numbers, setting a 'Numbers Only' preset significantly improves accuracy.

Why should I 'Binarize' an image?

Binarizing converts the image to strict black and white, increasing the contrast. This helps the OCR engine read faded scans or text with dark backgrounds more clearly.