Port / Reachability Check
ServerTCP-connect test to a host and port.
Uses a TCP connection attempt (no ICMP), so no elevated privileges are needed.
About the Port / Reachability Check
Is a service actually reachable? This free port checker tests whether a TCP port is open on any host by attempting a real connection from our server, with latency — no ICMP ping or software install required.
Use it to verify web, mail, database or game server availability.
How to check if a port is open
- Enter a hostname or IP and the port number.
- See whether the TCP connection succeeds, and how long it took.
- Check common ports like 80/443 (web), 25/587 (mail) or 22 (SSH).
What an open or closed port tells you
An open port means a service is listening and accepting TCP connections there — proof the service is reachable from the internet. A closed or filtered result usually means the service is down, bound only to localhost, or blocked by a firewall or security group. Checking from an external server, as this tool does, tests reachability the way a real client would.
Frequently asked questions
What does an open port mean?
An open port means a service is listening and accepting TCP connections there. A closed or filtered port means nothing is reachable, often due to the service being down or a firewall.
Why is a port shown as closed when the service is running?
A firewall or security group may be blocking external connections, or the service may be bound only to localhost. Check firewall rules and the service's bind address.
Does this scan many ports?
It tests the specific host and port you enter — a targeted reachability check, not a full port scan.
Why is a port closed when my service is running?
The service may be listening only on localhost rather than all interfaces, or a firewall/security group is blocking external connections. Check the service's bind address and your firewall rules.