Open apps safely on your Mac

macOS includes a technology called Gatekeeper that's designed to ensure that only trusted software runs on your Mac.

The safest place to get apps for your Mac is the App Store. Apple reviews each app in the App Store before it’s accepted and signs it to ensure that it hasn’t been tampered with or altered. If there’s ever a problem with an app, Apple can remove it from the store quickly.

If you download and install apps from the internet or directly from a developer, macOS continues to protect your Mac.

• When you install Mac apps, plug-ins and installer packages from outside the App Store, macOS checks the Developer ID signature to verify that the software is from an identified developer and that it has not been altered.

• By default, macOS Catalina and later also require software to be notarised, so you can be confident that the software you run on your Mac doesn’t contain known malware. An app that has been notarised by Apple indicates that Apple has checked it for malicious software and none was detected.

• Before opening downloaded software for the first time, macOS requests your approval to make sure you aren’t misled into running software you didn’t expect.

If your Mac displays an alert when you open an app

The warning messages displayed below are examples, and it's possible that you could see a similar message that isn't displayed here. Please use caution if you choose to install any software for which your Mac displays an alert.

Alert that the app was downloaded from the Internet

The first time you open a new app from an identified developer that you downloaded outside the App Store, your Mac asks if you’re sure you want to open it.

Alert that Apple cannot check the app for malicious software

If Apple can’t check an app for malicious software:

• Contact the app developer for more information

• Check the App Store for an updated version or search for an alternative app.

• If you’re certain the app is from a trustworthy source and hasn’t been tampered with, you may be able to temporarily override your Mac security settings to open it

Alert that the app developer cannot be verified

If the app developer can’t be verified and – in macOS Catalina and later – the app hasn’t been notarised by Apple, macOS can’t verify that the app is free of malware.

• Check the App Store for an updated version or search for an alternative app.

• If you're certain the app is from a trustworthy source and hasn't been tampered with, you may be able to temporarily override your Mac security settings to open it

Alert that the app wasn’t downloaded from the App Store

If your Privacy & Security settings allow apps from only the App Store, macOS won’t open an app that wasn’t downloaded from the App Store.

• If you're certain the app is from a trustworthy source and hasn't been tampered with, you may be able to temporarily override your Mac security settings to open it

• Change your Privacy & Security Settings to allow apps downloaded from both the App Store and identified developers

Alert that the app will damage your computer or the app is damaged

• If macOS detects that software has malicious content or its authorisation has been revoked for any reason, your Mac will notify you that the app will damage your computer.

• If macOS detects that software has been modified or damaged, your Mac will notify you that the app can’t be opened. The app may be broken or corrupted, or it may have been tampered with.

• If macOS detects known malware, your Mac will notify you that the app can’t be opened and move it to the Bin. You may be asked to anonymously share a copy of the malware with Apple to help improve macOS security. If you choose to share, macOS will only upload the malware executable itself (or the containing app bundle, if the executable is contained in a bundle) and nothing else.

If you want to open an app that hasn’t been notarised or is from an unidentified developer

Running software that hasn’t been signed and notarised may expose your computer and personal information to malware that can harm your Mac or compromise your privacy.

If you’re certain that an app that you want to open is from a trustworthy source and hasn’t been tampered with, you may be able to temporarily override your Mac security settings to open it.

After you've tried to open the app, follow these steps:

1. Open System Settings.

2. Click Privacy & Security, scroll down and click the Open Anyway button to confirm your intent to open or install the app.

   

3. The warning prompt reappears and, if you’re absolutely sure you want to open the app anyway, you can click Open.

The app will now be saved as an exception to your security settings, and you can open it in the future by double-clicking it, just as you can any authorised app.

Change the app security settings on your Mac

1. In System Settings, click Privacy & Security. Then scroll down to Security.

2. Under “Allow apps downloaded from”, select an option:*

   • App Store: Only allow apps that have been downloaded from the App Store

   • App Store and identified developers: Allow apps that have been downloaded from the App Store and from developers identified by Apple.

Privacy protections

macOS has been designed to keep you and your data safe while respecting your privacy.

Gatekeeper performs online checks to verify whether an app contains known malware and whether the developer’s signing certificate is revoked. We have never combined data from these checks with information about Apple users or their devices. We do not use data from these checks to find out what individual users are using on their devices.

Notarisation checks whether the app contains known malware using an encrypted connection that is resilient to server failures.

These security checks have never included the user’s Apple Account or the identity of their device. To further protect privacy, we don’t log IP addresses associated with Developer ID certificate checks, and we make sure any collected IP addresses are removed from logs.