Make PDF Searchable

A scanned PDF looks like a normal document, but it is really just a stack of images. You cannot select the text, search for a word, or copy a sentence — because as far as the computer is concerned, there is no text there at all, only a picture of it. This is where OCR (optical character recognition) comes in: it reads the shapes of the letters in the image and reconstructs the actual text.

ColaPDF makes your scanned PDF searchable by running OCR directly in your browser and adding an invisible text layer on top of each page. The page still looks exactly the same, but now you can search, select and copy the text. Because the recognition happens on your own device, sensitive documents — medical records, contracts, legal papers — never get uploaded to anyone. Only the generic OCR engine and the language model are fetched from a public CDN; your file stays with you.

How it works

1. Upload your scanned PDF using the drop zone or click to browse
2. Choose the language of the document so the text is recognised accurately
3. Click "Make Searchable" — each page is read with OCR in your browser
4. Download your searchable PDF — the text is now selectable and findable

Tips

• Choose the correct document language before running OCR — it dramatically improves accuracy, especially for accented text.
• For mixed-language documents, pick a combined option like Portuguese + English.
• The clearer the scan, the better the result. High-resolution scans of printed text give near-perfect recognition.
• OCR works page by page and can take a few seconds per page, so larger documents naturally take longer.

Frequently asked questions

Is my document uploaded anywhere?

No. The text recognition (OCR) runs entirely in your browser. Your PDF never leaves your device. Only the OCR engine and language model are downloaded from a public CDN — never your file.

What does "make searchable" mean?

A scanned PDF is really just images of pages, so you cannot select or search the text. OCR reads the text and adds an invisible text layer on top, so you can search, select and copy it.

How accurate is it?

OCR is very good on clear, printed text. Accuracy drops on handwriting, low-resolution scans, unusual fonts or multi-column layouts. Choosing the correct document language helps a lot.

Why does the first run take longer?

The first time you use a language, its recognition model (a few MB) is downloaded and cached. After that it is much faster.

Which languages are supported?

Portuguese, English, Spanish, French, German and Italian, including combined options like Portuguese + English for mixed documents.