Have you ever tried to use Ctrl+F to find a word in a scanned PDF, only to find that it doesn't work? This happens because the PDF is an "image-based" file. To your computer, the document isn't made of text; it's just a single, flat picture of text.
To make the text in that document selectable, copy-able, and searchable, you need to use a technology called Optical Character Recognition (OCR). This guide explains what OCR is and how you can use it to make your PDFs searchable.
What is OCR?
Optical Character Recognition is a process that converts images of typed, handwritten, or printed text into machine-encoded text. In simple terms, an OCR tool scans the "picture" of your document and identifies the letters and words, creating an invisible text layer on top of the image.
The result is a PDF that looks identical to the original scan but now has "real" text that you can search, copy, and highlight.
When Do You Need OCR?
- Scanned Documents: Any document that comes from a scanner is initially an image-only PDF.
- Photos of Documents: If you take a picture of a page with your phone, it needs OCR to become a functional document.
- "Flat" PDFs: Some PDFs are created in a way that flattens them into a non-searchable image.
How to Make a PDF Searchable with OCR
Performing OCR requires specialized software, as it's a computationally intensive process. While Docento.app is designed for annotating and signing existing text-based PDFs, you'll need a different tool for OCR.
Many free online OCR converters are available:
- Choose an Online OCR Tool: Search for "free online PDF OCR" and select a reputable service. Many of the tools in our top free editors list may offer this as a feature.
- Upload Your Scanned PDF: Select the image-based PDF from your computer.
- Select the Language: OCR works best when you tell it what language the document is in. Most tools will ask you to confirm this.
- Start the Conversion: The tool will process your file. This can take a few moments, especially for long documents, as it's a complex task.
- Download the Searchable PDF: The service will provide a new version of your PDF. Open it and try searching for a word—it should now work perfectly!
The Benefits of a Searchable PDF
- Find Information Instantly: No more manually scanning pages for a specific term.
- Accessibility: Screen readers can now read the document aloud, making it accessible to visually impaired users.
- Copy and Paste: You can easily copy text from the PDF to use in other applications.
Once you have your new, searchable PDF, you can easily edit or sign it using Docento.app.