Redact PDF

Redaction is one of the most misunderstood PDF operations. Many users apply a black rectangle PNG over sensitive text, call it redacted, and distribute the file — but the underlying text remains fully selectable, searchable, and accessible to anyone who removes the overlay. True redaction requires permanently removing the protected content from the PDF content stream itself, replacing it with opaque fill, and stripping any associated metadata that might reference the removed text.

PDF redaction workflows used in legal discovery, government FOIA responses, and privacy compliance follow a two-phase approach: first mark content for redaction (creating redaction annotations), then apply the marks — which destructively removes the underlying content from the page stream and flattens the redaction fill as page content. Once applied, there is no undo — the removed content cannot be recovered from the output PDF.

Common failure modes include: redacting only the rendered text while leaving the same text in metadata, bookmarks, or search indexes; partial redaction that misses headers/footers repeating the same content; and failing to redact content in attached files within the PDF. Our tool handles the content stream redaction and metadata clearing comprehensively.

Courts have seen cases where improperly redacted legal documents disclosed protected information — including witness identities, classified content, and attorney-client privileged communications — because the documents were 'redacted' by placing opaque shapes over text rather than removing the underlying data. When the recipient simply copied and pasted or ran the document through a text extractor, the 'hidden' content appeared in full. The US DOJ and federal court systems have issued guidance on proper PDF redaction specifically because this failure is so common. Proper redaction must modify the page content stream to permanently delete the data, not merely cover it visually.