open port checker

about open port checker

Test whether a specific port is open or closed on any hostname or IP address — useful for verifying firewall rules, server configurations, and network connectivity.

Checking whether a port is open is one of the most fundamental network troubleshooting tasks. This tool attempts a direct TCP connection to the specified host and port from our server, reporting whether the connection succeeded (port open) or was refused/timed out (port closed or filtered).

Common use cases include verifying that your web server is accepting connections on port 80 or 443, checking if SSH (port 22) is accessible after firewall changes, confirming database ports like MySQL (3306) or PostgreSQL (5432) are properly restricted, and testing if mail servers are reachable on port 25 or 587.

Quick-select buttons for the most commonly checked ports are provided for convenience. Simply enter the hostname or IP address, select or type the port number, and click check. Results are color-coded green for open ports and red for closed or filtered ports.

The check is performed server-side from our infrastructure, so results reflect whether the port is reachable from the public internet. This is different from checking ports on your local network, which would require testing from within that network.