Port Check Tool

Port Checker Tool is a tool for checking open ports on your computer or server.

For instance, if you are facing connection issue with a program (email, IM client, etc) then it may be possible that the port required by the application is getting blocked by firewall or ISP. In such cases, this tool might help you in diagnosing the issue.

It is often useful in testing port forwarding setup on a machine. It could also be useful for security reasons, in case you're worried whether a particular port is open or closed.