How to Fix "Developer Cannot Be Verified" on Mac Safely

Gatekeeper shows this alert when macOS can’t confirm an app’s developer or notarization. Check the App Store or developer for a signed build first. If you trust the source and still need the app, make the per-app exception below without turning Gatekeeper off.

#What Is Gatekeeper and Why Does It Block Apps?

Gatekeeper checks an app’s Developer ID signature and notarization before macOS opens it.

Apps from the Mac App Store pass both checks automatically. Apps downloaded from websites need at least a Developer ID signature to run without warnings. If an app has neither, Gatekeeper blocks it with the “developer can’t be verified” message.

Apple introduced Gatekeeper with OS X Mountain Lion in 2012, according to its contemporary Developer ID announcement. It doesn’t mean every blocked app is dangerous. Many legitimate open-source tools, small indie apps, and developer utilities lack Apple notarization because the developers haven’t enrolled in Apple’s paid developer program or haven’t submitted their apps for notarization review.

#How to Open a Blocked App With Right-Click?

Some macOS releases also offer a Control-click shortcut.

Right-click (or Control-click) the app in Finder and select Open from the context menu. A dialog appears warning that the app is from an unidentified developer. Click Open to proceed.

If macOS accepts the choice, it remembers the exception for that app. If the Open option doesn’t appear or the same alert returns, use Apple’s current System Settings path below.

Some Homebrew Cask apps and open-source utilities may show the same warning if a downloaded build isn’t notarized.

#Allowing Apps Through System Settings

According to Apple’s current safe-opening guide, try opening the app first, then approve that specific app through System Settings only if you’re certain the source is trustworthy and the app hasn’t been altered.

Go to System Settings > Privacy & Security and scroll to the Security section.

You’ll see a message saying the app was blocked. Click Open Anyway, confirm the warning, and authenticate if macOS asks. Apple says the button is available for about an hour after the blocked attempt and that macOS then saves the app as an exception.

Based on Apple’s security settings guide, you can also change the default app source to “App Store and identified developers” (which is the default) or lock it down to “App Store” only for stricter security. The stricter setting blocks all apps downloaded from the web, including notarized ones from identified developers, which is useful for shared Macs where you don’t want other users installing random software.

#Trust Checks Before Making an Exception

Change security settings only on your own computer or a Mac you’re authorized to administer. Bypassing organizational controls may violate workplace, school, or other applicable policies or laws, and an unverified app may expose personal or organizational data. On a shared or managed Mac, ask the owner or IT administrator instead.

Evaluate blocked apps before making an exception:

Trust indicators:

• The app comes from a well-known developer or project (Firefox, VLC, Homebrew, VS Code betas).
• You downloaded it directly from the developer’s official website, not a third-party download site.
• The developer provides SHA-256 checksums through an authenticated official channel, and you’ve verified that the downloaded file matches.

Warning signs that you should NOT open the app:

• You found it on a random forum or file-sharing site.
• It asks for admin permissions immediately after opening.
• The developer has no web presence, no GitHub profile, and no verifiable identity.

According to Apple’s Gatekeeper security overview, Gatekeeper verifies developer identity, notarization, and whether downloaded software has been altered. If macOS says an app will damage your computer or is damaged, don’t use Open Anyway; get a fresh signed copy or contact the developer.

#Avoid System-Wide Bypasses

Don’t disable Gatekeeper or strip quarantine metadata as a shortcut. Those changes go beyond Apple’s documented per-app route and may also violate a managed Mac’s policy. Use Open Anyway only for the app you reviewed; if that route isn’t available, stop and ask the developer or your IT administrator.

#Bottom Line

The “developer can’t be verified” alert means macOS couldn’t verify the app, not that the app is automatically safe or malicious. Check for a signed update or alternative first. If you trust the source and have authorization to use the Mac, approve only that app through System Settings > Privacy & Security > Open Anyway and leave Gatekeeper enabled for everything else.

#Related Mac App Problems

Read our macOS Gatekeeper overview for the security model behind the alert.

If the app is frozen rather than blocked, force quit the Mac app. If it opens and then behaves incorrectly, clear its damaged cache instead of changing security policy.

For an older Intel app, check Rosetta 2 compatibility. If macOS itself won’t install, follow the separate failed macOS installation guide. None of these failures calls for a Gatekeeper exception.

#Frequently Asked Questions