Website & server tools

Port checker

Test whether a TCP port is reachable from the internet — useful for checking port forwarding for game servers, cameras and remote access.

Defaults to your public IP. Only check systems you own or are allowed to test.
Common:

How it works

Our server tries to open a TCP connection to the address and port you enter. Open means a program accepted the connection; closed means the host refused it; filtered means nothing answered, usually because a firewall dropped it.

Port forwarding checklist

  1. Make sure the program (game server, camera, etc.) is running and listening on the port.
  2. Give the device a fixed local IP (DHCP reservation) in your router.
  3. Add a port-forwarding rule in the router (router login) from the public port to that local IP and port.
  4. Allow the port in the device's own firewall (for example Windows Defender Firewall).
  5. Check that you have a real public IPv4 address — if your ISP uses carrier-grade NAT, incoming connections can't reach you. See the public vs private IP checker.

Security

Only open the ports you need, keep the exposed software updated and use strong passwords. Remote desktop (3389) and camera ports are frequent targets; a VPN is safer than exposing them directly.

Questions

Why is my port filtered even though I forwarded it?

The most common causes are carrier-grade NAT at the ISP, the device's firewall, a second router in front of yours (double NAT), or the program not running.

Can I check UDP ports?

No. UDP has no connection handshake, so an external check can't reliably tell whether a UDP port is open. Test UDP services from the application itself.