How Optical Character Recognition (OCR) Works

1. PDF Page Rendering: When you upload a PDF, this tool first converts each page into a high-resolution image, right in your browser.
2. Text Recognition: It then uses the powerful Tesseract.js engine to analyze these images, recognize characters, and determine their exact position on the page.
3. Building a Searchable PDF: Finally, a new PDF is created. It places the original page image in the background and overlays the recognized text invisibly on top. The result looks identical, but now you can search, select, and copy the text.
4. Completely Secure: Your files are never sent to a server. The entire process, including the intensive OCR task, is performed locally on your computer.