How to black out text in a PDF — properly

"Black out text in PDF" is one of the most-searched document tasks — and the most dangerous one to get wrong, because a fake blackout looks identical to a real one.

The rectangle trap

Draw a black box in a typical editor and you've added a shape on top of the text. The words are still in the file: select the area, copy, paste into a text editor — there they are. This exact failure has exposed sealed court material and confidential business terms in public filings.

Blacking out text so it's actually gone

1. Open RedactSafe (free, in your browser — the file never uploads; it even works with wi-fi off).
2. Drag boxes over the text to black out. Auto-detect can mark SSNs, emails, phone and card numbers, amounts, and dates in one click; the search box redacts every occurrence of a name or term at once.
3. Export. Every page is re-rendered flat with the boxes burned in and the document rebuilt — the text under the boxes is not carried into the new file. Nothing to un-hide.
4. Review each page of the output before sending. The marking is yours; the destruction is guaranteed.