How to properly redact a PDF?

The best way to redact a PDF securely is to use a dedicated redaction tool that permanently removes selected text, images, and associated data. If you need to black out text in a PDF, do not rely on a black rectangle, highlighter, or annotation because the underlying information may remain searchable, selectable, or recoverable.

Always keep an untouched original. Applied redactions are intentionally permanent and usually cannot be undone.

• Built-in method

Redact a PDF with Preview on Mac

Current versions of Preview provide a built-in way to redact a PDF on Mac without installing additional software.

1. Duplicate the PDF and open the copy in Preview.
2. Select Tools > Redact or choose Redact from the Markup toolbar.
3. Drag over the text or area that must be removed.
4. Reopen the file and confirm that the information cannot be selected, copied, or searched.

You can undo a marked redaction with Command + Z only while the document remains open; closing Preview does not reliably discard the changes because the redacted content may still be saved. Preview is suitable for basic redaction, but a dedicated third-party PDF editor provides more control over repeated information and hidden document data.

Windows 10/11 do not include a built-in tool for secure PDF redaction. For anyone searching for how to redact a PDF without a redaction tool, Microsoft Edge is not a secure solution because drawing or highlighting only covers the information visually.

• Desktop applications

Because redaction usually involves private or confidential information, avoid online tools that require the PDF to be uploaded to a server. A desktop PDF editor that processes the file locally is generally more appropriate.

Permanently Redact a PDF for free with PDFgear

PDFgear is a free PDF editor for Windows and Mac that does not require an account or sign-in. If you are looking for how to redact a PDF without Adobe Pro, PDFgear includes a dedicated Redact tool that permanently removes selected text, images, or page areas.

1. Open a copy of the PDF in PDFgear.
2. Select Protect>Redact from the toolbar.
3. Mark the text, image, or page area containing sensitive information.
4. Apply and confirm the redactions.
5. Save the PDF under a new name and verify the removed content.

PDFgear lets you redact a PDF offline because all desktop features run locally, so the file does not need to be uploaded to a server. Keep the original document because applied redactions cannot normally be undone.

Redact a PDF with Adobe Acrobat Pro

For users searching for how to redact a PDF in Adobe, Acrobat Pro is the paid desktop option for removing visible content and hidden information on Windows or Mac.

1. Open a copy of the PDF in Adobe Acrobat Pro.
2. Select All tools > Redact a PDF.
3. Choose Redact text and images, then mark the sensitive content or search for repeated words and phrases.
4. Select Apply and remove hidden information when prompted.
5. Save the redacted PDF under a new name and verify it.

The free Adobe Acrobat Reader does not include the full Redact a PDF tool. Acrobat Pro can also search for a word or phrase and mark every matching instance for redaction, which is useful when the same sensitive information appears on multiple pages.

To confirm that the information has been permanently removed, save the redacted PDF, close it, and reopen the final copy. Search for the removed names, numbers, or email addresses, then try selecting and copying text around each redacted area into a plain-text editor. The removed content should not appear in search results, selections, or copied text.