Network tool
Open Port Checker
Test whether a TCP port is reachable on any public host or IP address, and see how long the connection took.
Checked live from Nxeon's servers. Real results, nothing mocked.
Enterchecks the port
What is a port checker?
Network services listen on numbered TCP ports — web servers on 80 and 443, SSH on 22, databases on ports like 3306 and 5432. A port checker attempts a TCP connection to a given host and port from the outside and tells you whether it succeeded. It's the quickest way to confirm a service is exposed and that no firewall is silently blocking it.
Common ports to test
- 22 — SSH remote access
- 80 / 443 — HTTP and HTTPS web traffic
- 25 / 587 / 465 — outbound and submission SMTP mail
- 3306 / 5432 — MySQL and PostgreSQL databases
- 6379 / 27017 — Redis and MongoDB
Frequently asked questions
Straight answers about how this tool works and what it can tell you.
What does 'open' vs 'closed / filtered' mean?
Open means our server completed a TCP handshake with that port — something is listening and reachable. Closed/filtered means the connection was refused or timed out, which can be a firewall dropping the packet, no service listening, or the host being unreachable.
Why is my port open locally but closed here?
This tool tests from the public internet inward. A port can be listening on the server yet blocked by a cloud firewall, security group, or the host's own firewall (ufw/iptables). If it's closed here but works locally, check those layers.
Can I check any port number?
Yes, any port from 1 to 65535. Use the quick presets for common services like SSH (22), HTTP (80), HTTPS (443) and databases, or type your own.
Do you scan private or internal addresses?
No. For security we resolve the host and refuse private, loopback, link-local and reserved ranges, so the tool can't be used to probe internal networks.
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