5 min read · Updated 2026-08-09
Blackout vs markup: hiding private text in a PDF
Why a black rectangle is not enough, when to use Blackout, and when Markup is the right tool.
Markup draws on top
Markup rectangles, lines, and notes are great for comments and highlights. A black markup box can look redacted on screen, but the original text often remains in the file for copy-paste or editing tools to recover.
Blackout flattens covered areas
SnapPDF Blackout paints opaque covers and flattens those pages so recipients cannot simply delete a shape to reveal what was underneath. Use it for ID numbers, addresses, and other private strings before you forward a file.
Still not forensic security
Everyday blackout is appropriate for school and office sharing. It is not a guarantee against every recovery technique. For highly sensitive material, follow your organization’s redaction policy and prefer official channels.