About This Tool
Some PDFs — scanned receipts, printed forms, old contracts run through a photocopier — are really just photographs of pages. There's no text underneath to select or search, which is why our regular PDF to Text tool comes up empty on them. This tool runs Optical Character Recognition (OCR) on those pages instead: it looks at the image of each page and recognizes the letters and words it contains, entirely inside your browser using WebAssembly, with no file ever uploaded anywhere.
When You Need This Instead of Plain Text Extraction
If PDF to Text returns "no selectable text found," the PDF has no text layer — it's a scan. That's exactly what this tool is for. If the PDF already has selectable text (you can highlight words in your PDF reader), use PDF to Text instead — it's faster and more accurate since it reads the actual text data rather than recognizing shapes in an image.
Practical Uses
- Digitizing paper records: pull text out of scanned invoices, old contracts, or printed forms so they can be searched and reused.
- Archiving: keep a text copy alongside a scan so the content is searchable without opening every file.
- Quick data entry: OCR a scanned table or list, then paste and clean it up in a spreadsheet instead of retyping by hand.
How Browser-Based OCR Works, and Its Limits
This tool uses Tesseract.js, a JavaScript port of the open-source Tesseract OCR engine, running as WebAssembly directly on your device's CPU. Each page of your PDF is first rendered to an image using pdf.js, then that image is fed to the OCR engine, which recognizes characters and outputs plain text — all without a server in the loop.
Getting the Best Results
- Higher-resolution scans OCR more accurately than blurry or low-DPI ones — 300 DPI or better works best.
- Straight, evenly-lit pages recognize far better than skewed or shadowed ones.
- Standard printed fonts recognize reliably; handwriting and decorative fonts are much less accurate.
- Always proofread OCR output against the original before relying on it — no OCR engine is perfect, and numbers/codes are worth double-checking.
Why It's Slower Than Other Tools
Because recognition runs on your own device's CPU rather than a specialized server, expect roughly 10-30 seconds per page depending on your device and page complexity — large multi-page scans will take a while. This trade-off keeps your files completely private: nothing is ever uploaded, so there's nothing to disclose in a privacy policy beyond the public OCR language files your browser downloads (never your document).
Frequently Asked Questions
Does OCR run on a server?
No — this tool uses Tesseract.js, which runs entirely inside your browser via WebAssembly. Your PDF file is never uploaded anywhere.
How accurate is browser-based OCR?
It works well on clean, high-contrast scans in common printed fonts. Accuracy drops on skewed pages, handwriting, low resolution, or unusual fonts — always review the output before relying on it.
Why is OCR slow?
Because it runs on your own device's CPU rather than a server, each page can take 10-30+ seconds depending on your device and page complexity. Larger scans take proportionally longer.