OCR PDF

Recognise the text in a scanned PDF and add it as an invisible layer over the page images, so the document becomes searchable, selectable and copyable while still looking exactly as it did. This is the step that turns a scan from a picture of a document into something you can actually work with, and it is a prerequisite for extracting text, tables or auto-redacting from any scanned file.

How to OCR a PDF

  1. Upload the scanned PDF.
  2. Choose the language or languages of the text in the document.
  3. Run the OCR - allow time, as this is by some margin the slowest operation on the site.
  4. Download the searchable PDF and test by searching for a word you can see on the page.

Frequently asked questions

Which languages are available?

This server has English, Indonesian, Arabic, Simplified Chinese and Traditional Chinese recognition data installed, together with orientation and script detection. Languages outside that set are not available here.

Can I select more than one language?

Yes, which is what a document mixing English with Indonesian or Arabic needs. Selecting languages the document does not contain tends to reduce accuracy, so keep the list tight.

The recognition quality is poor.

Accuracy depends on the scan. Aim for 300 DPI, straight rather than skewed pages, and good contrast. Running Adjust PDF Contrast first to clean up a grey background often makes a visible difference.

Does OCR change how the document looks?

No. The recognised text is placed as an invisible layer aligned to the page image, so the appearance is unchanged and the words are underneath where they appear.

Why is it taking so long?

Every page is analysed image by image, and concurrent OCR jobs on the server are deliberately limited so that one large document cannot starve everything else. A long scan can legitimately take several minutes.

Other optimisation tools

Files are uploaded over an encrypted connection and processed on CoonTool's own server, not in your browser. The working copy is deleted automatically once the job is done, and in any case within 24 hours. Nothing is stored permanently and no account is required.