Make Scanned PDF Searchable with OCR Online Free
Recognize text in a scanned PDF so it becomes searchable and selectable.
How to Make a Scanned PDF Searchable in 3 Steps
- Upload your scanned PDF. Drag and drop or browse for the scanned PDF that currently has no selectable text. This tool is specifically for image-based PDFs — if you can already select text in the PDF, it does not need OCR.
- Click "OCR PDF". PDFTools rasterizes each page at 300 DPI and runs it through Tesseract OCR to extract all recognisable text. The text layer is then embedded back into the PDF as a searchable overlay.
- Download your searchable PDF. Your processed PDF now has a selectable, searchable, and copy-able text layer added. The visual appearance of the scanned pages is completely unchanged.
Why Use PDFTools to OCR PDF?
- Makes scanned PDFs searchable — After OCR, you can use Ctrl+F to search for text in the document, select and copy text, and have the content indexed by document management systems.
- Powered by Tesseract OCR — Uses Tesseract — the industry-leading open-source OCR engine used by Google and trusted in professional document processing workflows globally.
- Visual appearance unchanged — The scanned page images remain exactly as they are. OCR adds a text layer behind the image — the document looks identical but is now searchable.
- English language support — OCR processing uses English language recognition for optimal accuracy on English-language documents. The engine performs best on clearly scanned, horizontal text.
Frequently Asked Questions
How do I know if my PDF needs OCR?
Open your PDF in any viewer and try to click on and select some text. If you can highlight and copy text, the PDF already has a text layer and does not need OCR. If you cannot select any text and the pages look like photographs or scanned images, the PDF needs OCR processing.
How accurate is the OCR text recognition?
Accuracy depends on the quality of the scan. Clearly scanned documents with standard fonts and good contrast typically achieve 95-99% accuracy. Faded originals, handwriting, unusual fonts, skewed pages, or very small text will have lower accuracy. For the best results, scan at 300 DPI or higher with good lighting and straight page alignment.
Can I run OCR on a PDF that already has some selectable text?
Yes, but you may get duplicate text layers. If only some pages of a mixed PDF are scanned, the OCR will add a text layer to every page. The existing text pages will have their original text preserved, and the scanned pages will receive the new OCR text layer.