About Port Checker & Network Port Security Reference
Interactive network port security reference and browser connection reachability tester. Inspect standard ports for Web (80, 443), Remote Shell (22), Mail (25, 587, 993), Databases (3306, 5432, 27017, 6379), and evaluate security risk levels and firewall rules.
Key Capabilities & Features
- Live browser connection probe for testable HTTP/HTTPS/WebSocket ports
- Comprehensive security encyclopedia for 20+ common TCP/UDP ports
- Vulnerability risk rating (High, Medium, Low) for exposed database and administrative services
- Actionable firewall hardening rules (e.g., block cleartext FTP, isolate Redis and MySQL to VPC)
- Filter ports by High Risk, Web Services, or Database engines
How to Use Port Checker & Network Port Security Reference
Select Target Host & Port
Enter an IP address or hostname and choose a port to test.
Run Probe
Click Probe Port to test whether the port responds or times out.
Review Security Reference
Consult the port catalog for vulnerability advisories and firewall recommendations.
Privacy & In-Browser Execution Guarantee
Probes network ports locally via browser fetch/abort timeouts. No server-side port scans are conducted.
Frequently Asked Questions
Can a web browser directly scan TCP or UDP ports on a remote server?
Browsers restrict raw socket creation for security. Web port checks utilize WebSocket/Fetch HTTP probes and comprehensive reference directories of standard port allocations.
Which network ports are most commonly targeted by attackers if left open?
Common targets include Port 21 (FTP), Port 22 (SSH), Port 23 (Telnet), Port 3389 (RDP), Port 445 (SMB), and unauthenticated database ports like 3306 (MySQL) and 6379 (Redis).
How can I close or secure an open port on my server?
Configure your operating system firewall (e.g. ufw deny 8080 on Ubuntu or Windows Defender Firewall) and bind backend services strictly to 127.0.0.1 (localhost).