Port Checker

Port checking tests whether a specific TCP port is open and accepting connections on a remote server. Every network service runs on a specific port number — web servers on port 80/443, SSH on port 22, MySQL on port 3306, and so on. An open port means the service is accessible; a closed or filtered port means the service is down, blocked by a firewall, or the port is unused.

This tool attempts a TCP connection to the specified host and port using PHP's socket functions. It reports whether the port is open (connection succeeded), closed (connection refused), or filtered (connection timed out). Network administrators, system engineers, and developers use port checkers to verify firewall rules, troubleshoot connectivity issues, confirm service availability after deployments, and audit exposed services for security hardening.

1. Enter host — Type a domain name or IP address into the Hostname/IP field.
2. Select port — Enter a port number manually (1-65535) or choose from the Common Ports dropdown.
3. Click Check Port — Press Check Port to attempt a TCP connection. The result shows open/closed/filtered status and response time.
4. Try examples — Use Valid Example for an open port or Invalid Example for a closed port.