Redaction looks simple: cover the secret part with a black box. But there's a dangerous catch — if you only draw a box over text, the original text usually still lives inside the file. Anyone can copy it out or recover it with a tool. This guide explains how to redact a PDF the right way.
Why black boxes fail
A highlighter or a black rectangle placed on top of a page is just a visual layer. The text underneath is untouched. Select-all and copy, or open the file in another viewer, and the "hidden" information reappears. Real redaction must delete the underlying content, not cover it.
What proper redaction does
True redaction removes the actual characters and image pixels inside the redacted area, then places a box on top. There is nothing left to recover. FreePDFtxt's Redact PDF tool works this way — the underlying text and image data are permanently erased.
Redact a PDF in a few steps
- Open Redact PDF and upload your document.
- Drag a box over anything you want to hide. Drag corners to resize, or move boxes to reposition.
- Use search to find a specific name or number, or the pattern tools to auto-mark every email, phone number, card number or ID at once.
- Optionally remove hidden document metadata (author, title) — a common leak.
- Click redact and download. The sensitive content is gone for good.
Tips for safe sharing
Always redact a copy, keep the original elsewhere, and double-check the result by trying to select text in the redacted areas. If you handle highly sensitive material, self-host the tool so files never leave your own server.
Protect your document: Redact a PDF now →