Every few months a court filing or government report makes the news because someone "redacted" it by drawing black boxes, and readers simply copied the hidden text out. A rectangle on top of a PDF hides text from the eye, not from the file.
A real redaction removes the content. This guide shows how to do that for free, in your browser.
Step by step
- Open the tool. Go to pdfmerger.io/redact-pdf. All pages of your file open on screen.
- Find what to hide. Type a name, an email address, an account number or any other text and click Find & mark. Every match on every page gets a box.
- Add boxes by hand. Drag over signatures, photos, stamps or anything the search can't find.
- Review. Click a box to remove it if it's not needed, or use Undo.
- Click "Apply redactions". The redacted PDF downloads.
Why this redaction is safe
Every page that has a box is rebuilt as a flat image with the black boxes burned in. The page's original text, images and drawings are not copied into the new file at all, so there is nothing underneath to recover. Pages without boxes are kept exactly as they were, with normal selectable text.
Document properties such as title and author are removed by default too, since they often give away what was redacted. Links that pointed into redacted pages are dropped.
Tip
Check the result: open the downloaded file, try to select text under a box, and search for the redacted word. Nothing should be found.
Black box vs. whiteout vs. redaction
- Black rectangle or highlight in an editor: hides the text visually; it can still be copied and searched.
- Whiteout: same problem, just in white. Fine for corrections, not for secrets.
- Cropping: hides content outside the crop box, which is still in the file.
- Redaction: removes the content. This is the only one to use for confidential information.
Don't upload what you're trying to protect
It is a strange idea to send a document full of personal data to a third-party server so that the personal data can be removed. Here the whole process runs inside your browser with pdf.js and pdf-lib. The original never leaves your device.
Frequently asked questions
Why can't I select text on redacted pages?
Because those pages are now images, which is what makes the redaction safe. If you need them searchable again, run the result through PDF OCR.
Can I redact a name everywhere at once?
Yes. Find & mark boxes every match on every page, and you can review them before applying.
Does it work with scanned PDFs?
A scan has no text to search, so draw the boxes by hand. They are burned in the same way.
Redact your document now: pdfmerger.io/redact-pdf.