A Black Box Is Not Enough
Drawing a black rectangle on top of a PDF leaves the original words sitting in the file underneath. Anyone can select the text behind the box, copy it, or delete the box and read it β a mistake that has exposed confidential data in court filings and corporate documents again and again. To black out text safely, the underlying content has to be destroyed, not just hidden.
This tool flattens the page: after you mark the areas to hide, each page is rasterised to an image with the black boxes burned in, and a fresh PDF is built from that image. There is no recoverable text or data left beneath the marks in the file you download.
Private by Design
Rendering, painting the boxes and rebuilding the PDF all happen in your browser, which matters most for exactly the kind of sensitive file you would redact. Nothing is transmitted to a server at any point.