PDF OCR — Make Scanned PDFs Searchable

About PDF OCR — Make Scanned PDFs Searchable

PDF OCR converts a scanned PDF — pages stored as flat images with no underlying text — into a searchable, copy-able document by running optical character recognition directly in your browser. Drop your file, pick which pages to process, choose a recognition language (English, French, German, Spanish, Portuguese, Italian, or Dutch), and the tool launches Tesseract.js in a worker and reads each page one at a time, showing per-page progress and confidence scores. The recognised text is then layered behind every page using pdf-lib, producing a brand-new PDF that looks identical to the original but lets you Ctrl+F to search, copy lines into other documents, and feed the file to screen readers. Because everything runs locally, sensitive scans of contracts, receipts, medical letters, and ID cards never leave your device.

Why use PDF OCR — Make Scanned PDFs Searchable

How to use PDF OCR — Make Scanned PDFs Searchable

1. Drop or select a scanned PDF — the tool reads its page count and shows a thumbnail picker.
2. Pick which pages to OCR (default: all pages) — useful if you only need text from a few key pages.
3. Choose the document's primary language so Tesseract loads the matching trained data file.
4. Click Run OCR and watch the per-page progress bar — each page reports a confidence percentage as it finishes.
5. Review the extracted text in the side panel and copy any snippet to the clipboard if needed.
6. Click Download Searchable PDF to save a new copy with an invisible text layer behind every page.

When to use PDF OCR — Make Scanned PDFs Searchable

• When a scanned contract or PDF arrives by email and you need to search for clauses or names without retyping.
• When archiving paper receipts and tax slips into a searchable PDF library before tossing the originals.
• When making old academic books or articles accessible to screen readers and full-text search.
• When preparing legal discovery materials so attorneys can grep for terms across thousands of scanned pages.
• When digitising handwritten notes or printed meeting minutes so they can be indexed by note-taking apps.
• When you receive a scanned ID or passport copy that needs to be parsed without uploading the file to a third-party service.

Examples

Tips

• Higher-resolution scans (≥ 300 DPI) produce dramatically better OCR results — rescan low-quality faxes if you can.
• If a page mixes two languages, pick the one with more text — Tesseract handles single-language documents most accurately.
• Crop or deskew the original before running OCR; even 2–3° of skew tanks recognition accuracy.
• Process big PDFs in batches of 20–30 pages at a time on mobile devices to avoid running out of memory.
• After downloading, verify by searching for a phrase you know is on page 1 — if it doesn't match, the language or scan quality probably needs adjusting.

Frequently Asked Questions

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Glossary

OCR

Optical Character Recognition — the process of converting page images into machine-readable text.

Searchable PDF

A PDF that retains its original visual layout but also embeds a text layer so the contents can be searched, copied, and read aloud.

Text Layer

An invisible layer behind a PDF's images that holds the recognised text and its on-page coordinates.

Tesseract.js

A JavaScript port of Google's Tesseract OCR engine that runs entirely in the browser via WebAssembly.

Confidence Score

A percentage Tesseract assigns to each recognised page indicating how certain it is of the read.

DPI

Dots per inch — the resolution of a scanned image; ≥ 300 DPI is the practical floor for reliable OCR.