Port Check
Test whether a TCP port is open on a host.
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Enter a host above and press Run to start the check.
About the Port Check
Port Check tests whether a single TCP port is open and accepting connections on a given host. It attempts a connection from the server and reports whether the port is open, closed, or filtered, which is the quickest way to confirm a service is reachable. Use it to verify that a web server, database, mail server, or game server is listening as expected.
How to use
- Enter the target hostname or IP address.
- Enter the TCP port number you want to test.
- Click Check to attempt a connection from the server.
- Read whether the port is reported open or closed.
Frequently asked questions
- What does an open port mean?
- An open port means a service is listening and accepted the TCP connection. A closed or filtered result means nothing answered or a firewall blocked the attempt.
- Does this test from my computer?
- No. The connection originates from this server, so it shows reachability from the public internet rather than from your local network.
- Why is a port I opened still showing closed?
- A firewall, NAT rule, or cloud security group may be blocking external access, or the service may be bound only to localhost.