How to black out text in a PDF so it is really gone
Last updated 27 September 2026
Every few months a court or a government publishes a document with black boxes over names, and somebody copies the text from under the boxes. It is the most common privacy mistake with PDFs. Here is how to do it properly.
Why a black box is not enough
In most PDF editors, a black rectangle is a new drawing laid on top of the page. The words underneath are still in the file. Anybody can select the black area, copy, and paste the text into an email. Search finds them too.
Real redaction takes the words out of the file. The tool here rebuilds every page that has a box on it as a picture, with the box painted in, so the covered words no longer exist in any form. Pages without boxes are kept as they were.
Black out every copy of a name or number
- Open Redact PDF and drop the document. It is never uploaded - which matters, because a document that needs redacting is one you should not upload.
- Type the name, phone number or account number and press Find. Every place it appears gets a box. Do this for each thing you need to hide.
- For anything Find cannot type - a signature, a photo, a stamp - drag across the page to draw a box by hand.
- Go through every page and check every box.
- Press Redact and save.
Remove the hidden details too
A PDF also carries things you do not see on the page: the author name, the program that made it, dates, comments, attached files, and sometimes older versions of the document with the words you deleted still in them. Drop the redacted copy on Safe to send. It lists everything it finds in plain words, and Take it all out removes it and checks the file again.
If you only want to change the title or author rather than remove everything, Edit PDF info does just that.
Check it before you send it
- Open the new copy in Open a PDF.
- Press Ctrl+F (Cmd+F on a Mac) and search for each word you hid. It must find nothing.
- Try to select the black boxes. Nothing should be selected.
One warning: a scanned page is a picture, so Find cannot see its words. On scans, draw every box by hand and check every page with your own eyes.