You're sharing a contract publicly but need to hide the parties' names and amounts. Drawing black rectangles over them isn't enough — anyone can select the text underneath and reveal it.
Real redaction removes the underlying text. The black bar is decoration; the data behind it is genuinely gone.
The difference between overlay and redaction
An overlay is a black box drawn on top of text. The text remains in the PDF. Select-all reveals it. Anyone can extract it. Not redaction.
Real redaction deletes the underlying text and replaces it with a visual mark. Select-all hits nothing. Extraction returns blank. The data is genuinely gone.
Redact in Flint
Use Flint's redaction tool. Select the text or area to redact. The tool removes the underlying content and overlays a black bar.
Save the redacted file. Confirm by trying to select the redacted text — there should be nothing to select.
Redact metadata too
Sensitive PDFs often carry sensitive metadata — author, creator software, modification history. Strip metadata before sharing publicly.
For maximum safety, also flatten the PDF after redacting. Layered structure can sometimes reveal redacted content in old file recovery.
FAQ
Is overlay redaction safe?
No. Anyone can copy the text underneath. Never use overlay for sensitive content. Use real redaction.
Will OCR text be redacted too?
Yes, when using proper redaction. The OCR layer is treated as text and removed in the redacted region.
Can redaction be undone?
No, if done properly. Keep a copy of the original if you need it later.
Does redaction work on images?
Yes — you can redact image content as well as text. Useful for hiding faces or sensitive details in scans.
Hiding text properly means redacting it. Use Flint's redaction tool — what's hidden stays hidden.