How to check that a PDF redaction really worked
A black box does not always remove the text beneath it. Learn how to check for recoverable text and unapplied redaction marks, and what a check cannot prove.
Quick answer
Run Redaction Checker to look for selectable text under dark boxes and for redaction marks that were never applied. A clean result is not proof of safety; fix problems with Redact PDF and check again.
What it checks
- Selectable text underneath solid dark boxes.
- Redaction annotations that are still marks, not applied removals.
- Pages it cannot check, such as image pages or rotated text, are listed separately.
What it cannot prove
Text can also hide in metadata, hidden layers, attachments, form fields, images and earlier file versions. Treat the result as one signal, then use PDF Privacy Inspection for the rest.