Redaction vs. white-out: how to hide private details in a PDF safely

4 min read · Updated November 1, 2026

Drawing a black box over text in a PDF feels like crossing it out with a marker. Usually it isn’t. The words are often still there, underneath, ready to be copied and pasted.

Why black boxes fail

Most PDF tools add shapes as a layer on top of the page. The original text stays in the file. Select across the box, copy, paste into a note, and the “hidden” details appear. This has embarrassed law firms, companies and government agencies whose court filings and reports were “redacted” this way.

The same goes for white-out, highlighting in black, and changing the text color to match the background. All of them hide; none of them remove.

What real redaction does

Real redaction deletes the content under the box. EditMyDocument’s Redact tool does it by flattening: when you save, every page with a redaction is rebuilt as an image with the black boxes burned into it. The original text on that page is not carried over at all, so there’s nothing left to copy.

How to redact a PDF

1. Open the file in Redact PDF.
2. Drag a box over each private detail. Cover the whole thing, with a little margin.
3. Check every page: account numbers often appear in headers and footers too.
4. Save, then open the saved file and try to select the blacked-out area. Nothing should come out.

What to redact

• Social Security and tax ID numbers (often only the last four digits need to stay).
• Bank and card numbers.
• Dates of birth, home addresses and phone numbers.
• Medical details and signatures of other people.