Port Checker
See which common ports are open
Test whether common service ports (web, mail, SSH, database and more) are open on a public host — a fast way to confirm a service is actually listening.
How to read the results
- 1.Enter a public host. We test a curated set of common ports (80, 443, 22, 25, 587, 993, 3306 and more).
- 2.Open means a service accepted a TCP connection; closed means nothing is listening or a firewall blocked it.
- 3.This is a diagnostic check of standard ports, not a full port scan.
Why it matters
When a service should be reachable but isn’t, checking whether its port is actually open separates a server problem from a firewall or DNS problem.
Frequently asked questions
Why only common ports?
This is a diagnostic tool, not a scanner. Checking a curated set of standard ports keeps it useful without enabling aggressive scanning of third parties.
A port shows closed but should be open — why?
A firewall may be filtering it, the service may be bound to a different address, or it is genuinely not running.