Port Checker

Port Checker is a tiny and portable software utility whose only purpose is to check whether a port is opened or not, based on data inputted by the user. It has limited features that can be figured out by anyone, even those with little or no experience in networking applications.
As there is not installation involved, you can drop the executable file to any location on the hard disk and just click it to run.
There is also the possibility of saving Port Checker to a USB flash disk or similar storage unit, in order to run it on any PC with minimum effort and without previously installing anything.
What's worth keeping in mind is that the Windows registry does not get updated with new entries (as it frequently happens with installers), and no extra files are created on the disk, leaving it clean after program removal.
The interface is represented by a regular window with a plain and simple structure, where all you have to do is specify a URL or IP address, along with the port number (from a drop-down list), and ask Port Checker to verify its availability with the click of a button. The result is immediately shown on the bottom part of the screen. Apart from the fact that you can clear it, there are no other notable options here.
Port Checker executes a task very quickly while using low CPU and RAM, so its impact on computer performance is minimal. We have not come across any type of issues in our tests, since the app did not hang, crash or pop up error dialogs.
Although it is not the most substantial tool out there, Port Checker gets the job done when it comes to verifying whether a particular port is opened or not.