What is OCR and what does it do to a scanned PDF?
A scanned PDF is usually just a stack of pictures of pages. To a computer, a photographed paragraph is no different from a photographed face: you cannot select the words, search them or copy them. OCR, short for optical character recognition, analyzes those pictures and works out which letters and words appear in them.
This tool runs an OCR engine over each page of your PDF and gives you the recognized text in a box that you can read and copy. The result is text, not a rebuilt searchable PDF.
When extracting text from a scan is useful
Typical jobs include pulling a paragraph out of a scanned contract to quote it, getting the text out of an old printed document so you can edit it, or copying figures from a scanned statement into a spreadsheet. It also helps when you need to search through a scanned document for a name or number.
If your PDF already contains real, selectable text, you do not need OCR. In that case PDF to Word will extract it directly.
How to run OCR on a PDF here
- Drag a scanned PDF onto the upload area, or click to choose it. The process starts automatically once the file is added.
- A progress bar shows while pages are being recognized. This can take a while for multi-page documents.
- When it finishes, the text appears in an Extracted text box. Pages follow one another in order, separated by blank lines.
- Press Copy to put the text on your clipboard, then paste it where you need it.
Each page is rendered as an image at 2x scale before being recognized, which helps the engine read small print.
Accuracy, language and what gets downloaded
The tool uses Tesseract.js, which runs inside your browser, so your PDF is not sent to a server. The engine and its language data are fetched the first time you use it, so the first run needs an internet connection and a short extra wait.
The tool is set up for English. Other languages and scripts are not offered, and text in them is likely to come out as garbage.
Accuracy depends mostly on the scan. Sharp, straight, high-contrast pages with clear printing give the best results. Skewed pages, faint ink, handwriting, small fonts and busy backgrounds cause mistakes. Always proofread numbers and names. If a page is sideways, fix it first with Rotate PDF.
There is no option to download a searchable PDF or a text file, so copy your result before leaving the page.