Port Checker
Test whether common or custom TCP ports are open on a host.
Frequently asked questions
What does the port checker do?
It tests whether specific TCP ports are open (accepting connections) on a public host — useful for confirming a service is reachable or a firewall change worked.
Which ports does it check by default?
A set of common ports including 21, 22, 25, 53, 80, 110, 143, 443, 465, 587, 993, 995, 3306, 3389 and more. You can also enter your own comma-separated list.
Can I scan any host?
Only public, internet-routable hosts. Private and reserved addresses are rejected, so the tool cannot be used to probe internal networks.