How to redact a PDF properly

A black box over words looks like a redaction and is not. The words are still in the file and still extractable — which is how sensitive information still travels after it was supposed to be gone. A real redaction rewrites the file so the words are no longer in it.

Last reviewed October 2026. If a page like this is ever rewritten, the date moves with it.

Why covering up fails

A white or black rectangle drawn over text paints above the words: on screen the text disappears, inside the file it is still there, in the content stream. Selecting the page, searching for the words, or opening the file in another editor all find them.

That is fine for tidying a form and completely wrong for an account number, a name or an address that must not travel. Covering up is for the eye; redacting is for the file.

What a real redaction does

The words within the rectangles you draw are removed from the page content, and a black rectangle remains where they were — the statement that something was here and is now gone. Only the marked text goes; text outside the boxes stays selectable and searchable, and images keep their resolution.

One page cannot be half-redacted from the inside: a page carrying both something you need and something you do not is better split — keep the part you want, delete the rest, or take the information out in the application that produced the document.

Check before you send

Open the redacted file and search for the words you marked — they should be missing. Selecting may catch a neighbouring word that was outside the box, which is why search is the right test.

Keep the original until the recipient has accepted the redacted copy. The tool writes a new file and never touches the original on disk, so the decision is reversible for as long as you keep the file you started with.

Questions

Does this truly delete the text?

Yes. The words inside the redacted rectangles are removed from the page content. Searching for them in the output returns nothing — unlike a box drawn over text, which hides it on screen but leaves it in the file.

Can I redact a scanned signature?

No. That signature is a picture, not text. Remove that page with the Organise tool, or take it out in the application that produced the document.

Will the black box print?

Yes. The rectangle is written into the PDF and prints with the page on every viewer and every printer.

Is the file uploaded?

No. The document is opened, rewritten and saved entirely in the tab. There is no server — you can verify in the network tab.

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