How to redact a PDF safely

Redaction means permanently removing sensitive information so it can never be recovered. It's one of the easiest things to get dangerously wrong.

The classic mistake

People drape a black rectangle over text and call it done. But if the underlying text is still in the file — just hidden behind a shape — anyone can select it, copy it, or strip the box away. There have been real-world leaks of court filings and reports where "redacted" text was recoverable with a copy-paste.

A visual cover-up is not redaction. If the data is still in the file, it isn't gone.

How to redact properly

• Use a tool that actually deletes the underlying content, or draw an opaque cover and then flatten / re-render the page so the text beneath is destroyed.
• Remember redaction isn't only text — check images, and remove sensitive metadata too (see removing metadata).
• Verify afterward: try to select text under the redaction, and search the file for the sensitive term.

Whiteout vs redact

A white cover ("whiteout") is fine for tidying up mistakes on non-sensitive documents. For anything confidential, use a genuine redaction that flattens the cover into the page so the content underneath is truly removed. FreshPDF offers both, and its exports rasterise edited pages so covered content doesn't survive.