How to Block a Program Using the Firewall on macOS

Unlike Windows, macOS features a streamlined, system-integrated firewall that’s designed for simplicity while maintaining robust security. While both operating systems offer protection against unauthorized network connections, the macOS approach focuses more on toggling permissions at the application level rather than creating detailed rule sets.
To block a specific application from accessing the network on macOS, you’ll need to enable the firewall, configure app-specific access, and pay attention to system alerts.

Step 1: Enable macOS Firewall Protection

Before you can block any apps, the firewall must be turned on:

• Click the Apple menu () in the top-left corner and choose System Settings (or System Preferences depending on your macOS version).
• In the sidebar, go to Network, then click on Firewall.
• Toggle the switch to enable the firewall if it’s currently turned off.

Note:

You may be prompted to enter your administrator password or use Touch ID to make changes. Once enabled, the firewall begins monitoring incoming connections and only allows trusted apps to communicate.

Step 2: Configure Access for Specific Apps and Services

Now that the firewall is active, you can block or allow specific programs:

• In the Firewall section, click on the Options or Firewall Options button.
• If the button is greyed out, make sure the firewall is turned on first.
• In the window that opens, you’ll see a list of applications currently allowed or denied access.
• To block a program, click the "+" button to add an application. Navigate to the app you want to block, and click Open.
• Once added, toggle the app's access setting to “Block incoming connections.”
• Click OK to apply and save your settings.

Important:

macOS only allows you to block incoming connections. Outbound connections (when apps initiate access to the internet) are not managed by the native firewall. You may need third-party tools like Little Snitch or LuLu for full control.

Step 3: Respond to Connection Alerts

macOS will notify you when an unrecognized app tries to establish a network connection:

• These alerts give you the option to Allow or Deny the connection.
• Pay close attention to these popups—they’re part of your firewall’s behavior and help you manage app permissions on the fly.

Tip:

Some system or signed applications may bypass firewall restrictions due to Apple’s built-in trust. While this enhances stability, it’s something to be aware of when managing custom apps or tools.

Additional Notes:

• To block all incoming connections (for apps not explicitly allowed), check the box labeled "Block all incoming connections" under Firewall Options.
• If you want to add more programs to your blocked list, repeat the steps above and adjust their permission levels accordingly.
• Always review and update your firewall settings after installing new apps to ensure they don’t bypass your configurations.