How do I turn scanned PDFs into searchable text with OCR?

To turn scanned PDFs into searchable text, you need to run OCR (Optical Character Recognition) on the PDF. Here are the main ways to do it:

1) Use built-in OCR in a PDF app

Many PDF tools can make scanned PDFs searchable:

• Adobe Acrobat Pro:
  Open the PDF → Tools → Scan & OCR → Recognize Text → save the file.
• Foxit PDF Editor, Nitro PDF, etc. often have similar OCR features.

This creates a PDF that still looks the same but now has selectable/searchable text behind the images.

2) Use free desktop tools

Tesseract OCR

Tesseract is a free OCR engine, often used from the command line.

A common workflow is:

1. Convert PDF pages to images
2. Run OCR on the images
3. Rebuild a searchable PDF or extract text

Examples:

• On Linux/macOS, you can use ocrmypdf:

ocrmypdf input.pdf output_searchable.pdf

This is usually the easiest free option because it:

• detects scanned pages
• adds a text layer
• keeps the original PDF appearance

You may need to install OCRmyPDF and Tesseract first.

3) Use online OCR services

There are websites where you upload a PDF and they return searchable text or OCR’d PDF files.

Be careful if the document is sensitive, private, legal, or confidential.

4) Automate with Python

If you need batch processing, you can use:

• ocrmypdf
• pytesseract
• pdf2image

Typical flow:

• convert PDF pages to images
• OCR each image
• save text or searchable PDF

Example with OCRmyPDF:

ocrmypdf scanned.pdf output.pdf

Best practices for good OCR results

• Use 300 DPI or higher scans
• Prefer black text on white background
• Deskew rotated pages
• Clean up blurry or dark scans if possible
• Use the correct language in OCR settings

If you want the simplest recommendation

If you want an easy free solution, use:

ocrmypdf input.pdf output_searchable.pdf

If you want, I can also show you:

• how to do this on Windows/Mac/Linux
• a step-by-step OCRmyPDF setup
• a Python script for batch OCR