How to Redact a PDF on Mac

If you use a Mac, your first instinct for editing a PDF is probably to open it in Preview — Apple's built-in document viewer. Preview is excellent for basic tasks like annotating, signing, and rearranging pages. But when it comes to redacting sensitive information, Preview has a troubled history that makes it unreliable for anything important.

This guide covers every method available for redacting PDFs on Mac, explains why Preview should not be your first choice, and shows you the fastest reliable alternative that works in any browser.

Why Preview Is Not Reliable for Redaction

For years, Mac Preview did not have any redaction capability at all. Its markup tools — including the rectangle shape, highlighter, and color fill — only added visual annotations on top of the PDF content. The underlying text remained fully intact and could be extracted by anyone who knew to look.

In more recent macOS versions (Sonoma and later), Apple added a dedicated "Redact" tool to Preview's Markup toolbar. This tool is supposed to permanently remove text. However, the transition has created confusion:

• Many users still use the wrong tool. The rectangle shape tool and the redaction tool look similar in the toolbar. Using the shape tool instead of the redaction tool results in a visual overlay that does not remove text.
• Older macOS versions do not have true redaction. If you are running macOS Monterey, Big Sur, Catalina, or earlier, Preview does not offer permanent redaction. Its markup tools only create annotations.
• Trust has been eroded. Years of Preview not supporting true redaction mean that many documents have been "redacted" with visual overlays. Security professionals generally do not recommend Preview for sensitive redaction tasks due to this history.

Method 1: AI-Redact in Your Browser (Recommended)

The most reliable and easiest way to redact a PDF on Mac is to use AI-Redact in your web browser. This approach works on every Mac regardless of macOS version, does not require any software installation, and provides AI-powered automatic detection of sensitive information.

Step 1: Open AI-Redact

Open Safari, Chrome, Firefox, or any other browser on your Mac and navigate to the AI-Redact tool. The application loads entirely in your browser — no plugins, extensions, or downloads are needed.

Step 2: Upload Your PDF

Drag your PDF from Finder directly into the browser window, or click the upload area to use the file picker. The file is encrypted using TLS 1.3 during upload and is never stored on the server after processing.

Step 3: Review AI Detections

Within seconds, the AI scans every page and highlights detected sensitive information. It identifies names, email addresses, phone numbers, Social Security numbers, dates of birth, home addresses, and financial account numbers. You can adjust the selections — removing items you want to keep visible or adding additional areas to redact.

Step 4: Download the Redacted PDF

Apply the redaction and download the result. The redacted PDF will be saved to your Mac's Downloads folder. The sensitive text is permanently removed from the file — it cannot be selected, searched, copied, or recovered.

Method 2: Preview Markup (macOS Sonoma and Later Only)

If you are running macOS Sonoma or later and want to use Preview, here is how to access the dedicated redaction tool. Note that we still recommend AI-Redact for sensitive documents.

1. Open the PDF in Preview (double-click the file or right-click > Open With > Preview).
2. Click the Markup toolbar button (pencil icon) to show the Markup toolbar.
3. Look for the Redact tool — it appears as a filled black rectangle icon, distinct from the shape tool. Click it.
4. Click and drag over the text you want to redact. The area will be highlighted.
5. When you save the file, Preview will apply the redaction and permanently remove the text. Note: you must save the file for the redaction to take effect.

Important: Do not use the shape tool (rectangle), highlighter, or any other markup tool for redaction. Only the dedicated Redact tool removes the underlying text data.

Method 3: Adobe Acrobat Pro on Mac

Adobe Acrobat Pro DC is available for Mac and includes a professional-grade redaction tool. The workflow is the same as on Windows: open the PDF, go to Tools > Redact, mark content for redaction, and apply. This is a reliable option if you already have an Acrobat Pro subscription ($239.88/year).

However, Acrobat Pro does not include AI-powered automatic detection. You must manually identify and mark every piece of sensitive content, or use the "Find Text & Redact" feature to search for specific words or patterns. For a 20-page document, this process can take 15-20 minutes compared to about 10 seconds with AI-Redact.

Method 4: Command-Line Tools (Advanced)

For technically inclined Mac users, there are command-line approaches using tools like qpdf, pdftk, or Python libraries such asPyMuPDF. These allow programmatic text removal from PDFs but require programming knowledge and are impractical for one-off redaction tasks. They are better suited for automated pipelines where the same redaction rules need to be applied to hundreds of documents.

Keyboard Shortcuts for Mac PDF Workflows

Here are some useful keyboard shortcuts for working with PDFs on Mac:

• Cmd + O: Open a file in Preview or Acrobat
• Cmd + S: Save (applies pending redactions in Preview)
• Cmd + Shift + S: Save As (create a new copy with redactions)
• Cmd + F: Find text (use this to verify redaction worked)
• Cmd + A: Select all (use this to test if redacted text is still selectable)