Port Checker is a free online tool which checks a remote computer or device accessibility from the Internet. It can be used to check open ports or Ping a Port on a remote server. TCP Port Checker tries to establish connection from our server and if the connection is successful or it receives a port open signal, you should be able to see it. You can't use this tools to check local ports in your computer.. The compute and device needs to be connected to internet directly or a port must be forwarded to the computer if you are connecting it through a router.