Redact a PDF online
Permanently redact sensitive text and images from PDFs. Cover with black rectangles and flatten so the original content can't be recovered.
Redacting a PDF means permanently removing sensitive content — names, account numbers, social security numbers, addresses, photos, anything that shouldn't reach the recipient. The mistake most people make is using the highlighter tool with black ink, or covering text with a black image overlay that the recipient can copy-paste underneath. Real redaction has to remove the data from the file, not just hide it visually.
PDFOnly's redaction workflow uses Edit PDF to overlay filled black rectangles on sensitive areas, then Compress PDF to flatten those rectangles into the page content (the compression process rasterizes the page region, eliminating the underlying text data). The combination produces a permanently-redacted PDF where copying from beneath the black box returns nothing — the original text is gone from the file structure.
Frequently asked questions
Why does adding a black rectangle on top of text not actually redact it?
PDFs are layered. The black rectangle is one object; the text underneath is another. A determined recipient can copy-paste the redacted area, paste into a text editor, and see the underlying text — even though it's visually hidden. True redaction has to remove the text data from the file, not just cover it.
Does compression after the rectangle actually remove the original text?
Yes when done right. Compression often rasterizes the page (turns it into an image at the chosen DPI), which destroys the text layer in that area. Combine Edit PDF (rectangles) + Compress PDF (high preset) for permanent redaction. For absolute guarantees, use a dedicated redaction tool that explicitly removes objects from the PDF structure.
What's the most secure redaction method?
True content removal: extract the text, remove the sensitive parts, regenerate the PDF without those parts. Tools like Adobe Acrobat's redaction feature do this. PDFOnly's rectangle + compression workflow is a strong substitute for most use cases but isn't auditor-grade for high-stakes legal redaction.