Port Checker
FreeEnter a public host and TCP port to test whether the service accepts a short connection attempt.
Related tools
Other utilities you may need.
How to use Port Checker
Enter a hostname and port. The server attempts a short TCP connect and reports open or closed.
Understanding the results
Open means a short TCP connect succeeded. Closed or filtered means the connect did not succeed from this checker.
Limitations
- Private targets are blocked.
- Firewalls and rate limits can make a reachable service appear closed from this location.
Privacy note
Only the host and port you enter are used for the connectivity probe.
Frequently asked questions
What does open or closed mean?
Open means the short TCP connect succeeded. Closed means it did not succeed from this checker.
Which ports can be tested?
Common public TCP ports can be tested when the target is publicly reachable.
Why are private targets blocked?
Private and local addresses are blocked to prevent scanning non-public networks.
Do I need an account?
No account is required for free tools on this site.