Port Checker

Port Checker — Check if a Port Is Open, Free

Check whether a TCP port on a public server accepts connections, straight from your browser. Enter a hostname or IP address and a port number, and get an instant Open, Closed, or Filtered result.

How to Check a Port

Enter a hostname or IP address, then a port number — or use one of the quick-pick chips for common ports like HTTP (80), HTTPS (443), SSH (22), or MySQL (3306). You can check up to five ports in a single request. The check runs from our server, not your own connection, so it shows whether the port is reachable from the wider internet, not just from your network.

What Each Result Means

Open means something on that server accepted the connection — a web server, mail server, database, or similar. Closed means the host responded but nothing is listening on that specific port. Filtered means there was no response at all, which usually points to a firewall silently dropping the connection rather than actively refusing it. A port can look different from here than it does from your own network — a firewall rule might allow your office IP but block everyone else, for example — so use this alongside your own local testing, not as the only check.

Common Uses

Confirming a new web or mail server is actually reachable after setup, checking that a firewall rule is working as intended, or troubleshooting why a service isn't reachable from outside your network. Only test hosts you own or have permission to test.