How to Redact in Preview on Mac — Permanently Remove Sensitive PDF Content

Redacting sensitive PDF data is essential for secure file sharing. While Mac Preview offers free built-in redaction, it suffers from notable drawbacks, including limited batch processing and incomplete data sanitization.

This guide shares valid Preview redaction tips and explores UPDF, a robust alternative that fixes Preview’s common redaction flaws for more reliable results.

Part 1. Is Preview Enough for You?

Wondering if Mac Preview meets your PDF redaction needs? Check if Preview can fit your scenario.

Your Scenario	Is Preview Enough?
Small PDF, occasional redaction, simple text	✅ Yes
Redacting text AND images	✅ Yes
Large PDF with many sensitive terms	⚠️ Maybe
Need to redact the same word across 100+ pages	❌ No
Need to redact an entire page or multiple pages	❌ No (Preview doesn't support page‑level redaction)
Need automated redaction of patterns (e.g., all phone numbers)	❌ No
Need to sanitize metadata after redaction	❌ No
Privacy‑critical document — must be 100% secure	✅ Yes (Preview's redaction is permanent)

Preview's redaction tool is secure and permanent — it's not just visual. But it's manual. If you're redacting one or two items, Preview is perfect. If you're redacting dozens of items across a long document, you'll want a professional tool. Go to Part 3 to check which professional tools suit you best.

Part 2. How to Redact in Preview - Step-by-Step Guide

Conveniently, Preview on macOS makes it easy to redact text without having to grab a Sharpie. Just before you start, make sure you understand that redaction is permanent.

⚠️ Always work on a copy of your original document.

Redaction in Preview is permanent and irreversible. Once you save, you cannot undo it. Always duplicate your document before you begin.

Step 1: Duplicate your document.

Remember, redaction is permanent. To safeguard against accidental loss of important information, the first step is to duplicate your document. This way, you preserve the original content before you make any changes. Right-click your document in Finder, select "Duplicate," and a copy will be created. For demonstration, we will duplicate a document named "whitepaper".

Step 2: Open your document with the Preview App.

With the duplicate saved, open your PDF in Preview. Right-click the file, then hover over Open With and choose Preview. The document will open in a new Preview window, where you will have the ability to edit the document.

Step 3: Open the Markup Toolbar.

To use the Redaction tool, you will have to open up the Markup Toolbar first. Click on the blue icon to display the Markup Toolbar.

Step 4: Select the Redaction tool.

The redaction tool is represented by a filled-in square icon located third from the left within the Markup Toolbar. Activating it allows you to click-and-drag to select/redact parts of the document. When clicked, a warning will also pop up alerting the user to the permanence of the action once a document is saved.

Step 5: Implement the redaction.

To redact, click and drag your cursor across the segments you wish to conceal, whether text or images. For instance, in our example, we're targeting text in the document's upper left corner. This tool is versatile, allowing you to obscure any part of your document, including images, ensuring comprehensive privacy protection.

Step 6: Save your changes.

When you are certain you have adequately redacted any and all areas meant for redaction, go ahead and save your document. This is the step that makes your redactions permanent, so they are no longer reversible.

By following these steps, you will now know how to use the redact tool in Preview and have confidence that sensitive content in your document is safely obscured.

Note: Preview does not support blurring or pixelation — and that's actually a security feature. Blurring and pixelation can sometimes be reversed. Preview's solid‑black redaction is more secure

Preview's redaction tool is useful, but it has significant limitations. Understanding them will help you decide when to use Preview and when to upgrade.

Limitation	Why It Matters	What to Use Instead
No search‑and‑redact	If a sensitive word appears 100 times, you must manually find and redact each instance	Professional tool with search‑and‑redact
No page‑level redaction	Cannot redact entire pages at once	Professional tool with page redaction
No pattern redaction	Cannot automatically redact all phone numbers, emails, or SSNs	Professional tool with auto‑redact
No metadata sanitization	Hidden metadata (author, creation date, etc.) remains	Professional tool with sanitize function
No batch processing	Must redact one file at a time	Professional tool with batch redaction
Cannot edit existing text	Preview can't edit the original text of a PDF	Professional PDF editor
No OCR for scanned PDFs	Cannot redact text in scanned documents	Professional tool with OCR

Preview forces you to visually scan every page and manually select every piece of content to redact.

For a 10‑page document with one or two sensitive items, this is fine.

For a 100‑page contract with a confidential name that appears 50 times, this is a time‑consuming, error‑prone process.

Even after you redact visible content, PDFs often contain hidden metadata — the author's name, the creation date, editing history, comments, and other information that can reveal sensitive details.

Preview's redaction tool removes visible content but does not sanitize metadata. Professional tools offer a "Sanitize Document" feature that removes this hidden information.

Part 3. How to Fix Mac Preview Redact Not Enough or Not Working?

Many Mac users encounter incomplete or failed redaction in Preview. Try three fixes: switch to an offline alternative like UPDF, update macOS to the latest version, and check for corrupted PDF files causing malfunctions to securely erase private content.

Fix 1. Best Professional Alternatives for Mac Preview

If Preview's limitations are holding you back, here are the best professional alternatives for Mac.

Tool	Pricing	Search‑and‑Redact	Page Redaction	Auto‑Redact Patterns	Metadata Sanitization	Batch	OCR	Platform
UPDF	One‑time ($79.99)	✅	✅	✅	✅	✅	✅	Win, Mac, iOS, Android
Adobe Acrobat Pro	Subscription (~$240/year)	✅	✅	✅	✅	✅	✅	Win, Mac
Foxit PDF Editor	Subscription (~$130/year)	✅	✅	✅	✅	✅	✅	Win, Mac
PDF Expert	Subscription (~$80/year)	✅	✅	❌	❌	❌	❌	Mac, iOS
Preview	Free	❌	❌	❌	❌	❌	❌	Mac

UPDF excels in PDF redaction with instant text/page/AI pattern redaction, sanitization, batch & OCR tools, full offline privacy, and a one-time $79.99 fee, far cheaper than Adobe’s $240 annual subscription while eliminating manual work and data leaks.

Redacting documents efficiently is crucial, and UPDF offers a straightforward solution. Here's how you can utilize UPDF for your redaction needs:

Begin by downloading UPDF via the UPDF official website or the button below. It provides versions for various operating systems, ensuring compatibility with your device.

With UPDF installed, locate the PDF you wish to redact. Right-click the file, select 'Open With,' and choose UPDF.

Navigate to "Tools" in the left-column menu toolbar in UPDF and click on the Redact tool. A prompt will appear, reminding you that redaction is irreversible. Acknowledge the warning to proceed.

UPDF presents three redaction tools at the top toolbar: Mark for Redaction, Redact Pages, and Find Text & Redact. Unlike Mac Preview, UPDF includes options for redacting entire pages or searching for specific text to redact.

Select 'Redact Text & Images' to activate the cursor for covering text. Drag the cursor over the text in the upper left corner, or any section you intend to hide, ensuring it's completely covered.

After completing the redaction process, go to the arrow next to "Save" and select "Save as..." to save your document. Saving applies the redactions permanently to your PDF.

There you have it – redacting PDF documents is straightforward with UPDF, backed by awesome tools for all of your document management needs.

For more information about UPDF's capabilities, read an in-depth review where you can learn about all the different features that UPDF offers.

Fix 2. Update Your MacOS Version

Unfortunately, the Preview app on Mac is only available if you are running macOS 11 or newer. If you're running an older version of the platform (say, macOS 10.14 or lower), you're out of luck. The step to solving this problem is an easy one, though: update your macOS. Once your system is using the current macOS version available, redaction capabilities will be enabled in Preview. After you've updated your macOS, restart your system for the changes to take effect and check to see if redaction is accessible.

Fix 3. Ensure Correct Document Opening Method in Preview

Opening the document correctly in Preview is essential. When using the "Quick Look" feature, you're just peeking into a document, and that particular view doesn't support redaction. You need to actually open the document in the Preview app in order to access the redaction tools. So, if you're not able to locate a redaction tool icon, go back to the step-by-step guide and pay close attention to Step 2 to make sure you are opening the document correctly.

Final Thoughts

All in all, knowing how to redact in Preview is key to document security and privacy.

Master these processes, and you can rest assured your documents are secure. And that just emphasizes how important the right to privacy is in our communication nowadays.

For those who are more advanced, and those who run into trouble with Preview, UPDF is a great alternative. It has the best of both worlds and much, much more beyond redaction.

This guide covers everything you need to redact in Preview on Mac. If you're looking for a more comprehensive walkthrough on PDF security — password protection, encryption, redaction, digital signatures, and more — visit the best 9 PDF Encryption Software to find what you need.