How to redact a PDF properly

Why a black box is not enough

Drawing a black rectangle over text in a PDF editor, or highlighting it in black, only covers it. The words usually stay in the file underneath, and anyone can select, copy or search them. Real redaction removes the content itself.

How to redact a PDF

1. Open Redact PDF and add your file.
2. Draw a box over each area to remove. Drag on the page, and remove a box by clicking its X if you make a mistake.
3. To catch every occurrence of a name, number or phrase, type it into Find text, check the yellow matches, and click Redact all. There are shortcuts for emails and phone numbers.
4. Choose the quality of the redacted pages, then click Redact.
5. Download the new PDF.

What happens to the file

Every page with a redaction is drawn to an image with your boxes painted black, and that image replaces the page. The text under the boxes is not in the new file. Pages without redactions are copied unchanged, and the document's old title and author details are not carried over.

After redacting, Foldline re-opens the result and confirms that the redacted pages contain no selectable text.

Check your work before you share

• Look through every page. Redaction only affects the pages where you added boxes, so sensitive details on other pages stay.
• Search for the sensitive words in the new file with your PDF viewer. Redacted pages should find nothing.
• Keep your original in a safe place. Redaction can't be undone in the new file.

Scanned documents and searching

Text search only works where the PDF has real text. For a scanned page, draw boxes by hand, or run OCR PDF first and then search. Redacted pages are images, so they are no longer searchable. If you need a searchable copy, run OCR PDF on the result: the blacked-out parts stay unreadable.