How to Redact a PDF (and Why a Black Box Isn’t Enough)

Before you share a contract, medical record, or bank statement, you need to hide the sensitive bits — names, account numbers, addresses. But drawing a black box over text in most PDF viewers is a trap: the words are still there, sitting underneath the box, fully selectable and copyable. Real redaction removes the content, not just hides it.

Why “black box” redaction is dangerous

This mistake has leaked confidential data in court filings, government reports, and corporate documents more times than you'd think. When you place a filled rectangle over text, you've only added a graphic on top — the original text layer is untouched. Anyone can select the “hidden” text, copy it out, or simply move the box. Proper redaction deletes the underlying words so there is nothing left to recover.

What proper redaction does

• Permanently removes the selected text and image data from the file
• Leaves a solid mark where the content was, with nothing beneath it
• Cannot be undone by selecting, copying, or moving a box

Step-by-step: redact a PDF with ToolsGravity

1. Open the PDF Redact tool and upload your document.
2. Mark the areas or text you need to remove.
3. Apply the redaction — the content underneath is deleted, not covered.
4. Download the redacted PDF and verify: try to select text in the redacted areas. There should be nothing to select.

What to redact before sharing

Don't forget the metadata

Redacting the visible page isn't always enough — a PDF can carry hidden data in its metadata (author, software, edit history) and in attachments. After redacting, run the file through the PDF Sanitize tool to strip hidden metadata, or clear specific fields with the PDF Metadata Editor. Always open the final file and double-check before sending.

Summary

Never rely on a black box — it hides text on screen but leaves it fully recoverable in the file. Use true redaction to permanently delete the content, redact every category of sensitive data, and sanitize the metadata afterwards. The ToolsGravity PDF Redact tool removes the underlying data so what you hide stays hidden.