What is PDF Redaction?
Permanently removing sensitive text or images from a PDF — not just covering them with a black box.
True redaction deletes the underlying content from the PDF object stream and replaces it with an opaque mark. A black rectangle drawn on top of text is not redaction — the text remains selectable and recoverable. Legal, medical, and government workflows require certified redaction tools.
Also known as
- PDF blackout
- secure redaction
Related terms
- PDF Encryption — Cryptographic protection that requires a password to open or modify a PDF — typically AES-128 or AES-256.
- PDF Permissions — Flags inside a PDF that limit actions like printing, copying, or editing — enforced by viewers, not cryptography.
Category: Security