{"id":104827,"date":"2026-06-26T05:35:43","date_gmt":"2026-06-26T12:35:43","guid":{"rendered":"https:\/\/www.intego.com\/mac-security-blog\/?p=104827"},"modified":"2026-06-26T05:39:25","modified_gmt":"2026-06-26T12:39:25","slug":"what-is-macos-gatekeeper","status":"publish","type":"post","link":"https:\/\/www.intego.com\/mac-security-blog\/what-is-macos-gatekeeper\/","title":{"rendered":"What is macOS Gatekeeper and how do you use it?"},"content":{"rendered":"

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If you\u2019ve ever downloaded an app from outside the App Store, you\u2019ve probably seen Gatekeeper in action. You don\u2019t usually need to set it up yourself because macOS keeps it enabled by default.<\/p>\n

Its job is to make sure downloaded apps come from a trusted source, haven\u2019t been altered, and don\u2019t match known malware checks. If an app doesn’t pass these checks, Gatekeeper may warn you, block it, or ask you to confirm that you want to open it.<\/p>\n

This guide explains what Gatekeeper does, how to review its settings, what to do if it blocks an app you trust, and how it compares with dedicated Mac antivirus software.<\/p>\n

What is macOS Gatekeeper?<\/h2>\n
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Gatekeeper is a built-in macOS security feature that checks downloaded apps before they open. It helps make sure the software comes from a trusted source and can be verified by macOS.<\/p>\n

Whenever you download software from outside the App Store, Gatekeeper checks whether it was signed by an identified developer and whether macOS can verify the app.<\/p>\n<\/div>\n

It also checks whether Apple has notarized the app. Notarization means Apple has scanned the software for known malicious content and confirmed that the developer signed it for distribution outside the App Store.<\/p>\n

If the app hasn\u2019t been notarized, has been altered since it was signed, or fails other security checks, Gatekeeper may block it or show a warning before it runs.<\/p>\n

When you open a downloaded app for the first time, Gatekeeper may ask you to confirm that you want to proceed. This extra step keeps you from accidentally opening software you didn\u2019t intend to run.<\/p>\n

You don’t need to set up Gatekeeper manually. It’s enabled by default on your Mac and is designed to work automatically in the background.<\/p>\n

What does Gatekeeper check on a Mac?<\/h2>\n

When you first open a downloaded app, Gatekeeper checks whether macOS can verify the app, whether it has been altered, and whether it matches known malware checks.<\/p>\n

First, it checks whether the app was signed by an identified developer. This helps macOS verify the source of the app and check whether it has been altered since it was signed.<\/p>\n

It also looks to see if the app has been notarized. This means Apple has already checked the software for known malicious content before allowing it to be shared outside the App Store.<\/p>\n

Gatekeeper also checks whether Apple has flagged the app for known malware or revoked the developer\u2019s signing certificate. If macOS can\u2019t verify the app, or Apple\u2019s checks identify a known safety issue, Gatekeeper may block the software from opening.<\/p>\n

Gatekeeper doesn\u2019t continuously scan your whole Mac like dedicated antivirus software<\/a>. It mainly checks downloaded software when you open it, making it a useful first layer of protection rather than a full malware scanner.<\/p>\n

How to check Gatekeeper settings on your Mac<\/h2>\n
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To check your Gatekeeper settings:<\/p>\n

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  1. Open System Settings<\/strong>.<\/li>\n
  2. Select Privacy & Security<\/strong> from the sidebar.<\/li>\n
  3. Scroll down to the Security<\/strong> section.<\/li>\n
  4. Look for Allow applications from<\/strong>.<\/li>\n<\/ol>\n

    This is where you can see which app sources macOS allows by default. The exact wording depends on which version of macOS you are running, but you\u2019ll generally see two choices:<\/p>\n