ZoneAlarm has been synonymous with personal firewall excellence. Our 2026 review tested ZoneAlarm Pro on Windows 10 and 11. The firewall blocked all 50 of our outbound connection tests to simulated command-and-control servers. In stealth mode testing, our test PC became completely invisible to external port scans. The Two-Way Firewall monitors both inbound and outbound traffic. ZoneAlarm’s OS Firewall Anti-Exploit module blocked all 25 exploit kit simulations. Identity protection monitors your personal information across breach databases. Anti-Keylogger blocked all 20 keylogging tools in our tests.