- Shields Up! - Internet Connection Security Analysis
- PC Flank - Make sure you are protected on all sides
- HackerWhacker - Hack Yourself - Remote Computer Network Security Scan
- DSL Reports
- Sygate Online Services
- Audit My PC: Firewall Test, Port Scan, and Security Test
- WinNuke Test Page
- Security Space Security Audits
- Port Scan Security Check
- CyberCop: Online Vulnerability Assessment Service
Port Scanners
