Open Port Checker
Check whether a port on your own internet connection can be reached from outside, for game servers, cameras, self-hosted apps and port forwarding.
How to open a port
- Find the local IP address of the device running the service, for example
192.168.1.50. It is in the device's network settings. - Log in to your router, usually at
192.168.1.1or192.168.0.1, and find the port forwarding section. It may be called virtual servers or NAT. - Forward the port (TCP, or TCP and UDP if the app needs both) to that local address.
- Allow the port through the firewall on the device itself.
- Make sure the service is running, then test again here.
Give the device a fixed local address (a DHCP reservation on the router), or the forward stops working when its address changes.
When it still does not work
- CGNAT. Some providers, especially mobile and fibre networks, share one public address between many customers. If the WAN address in your router does not match the address shown on What Is My IP, you are probably behind CGNAT, and port forwarding cannot work. Ask your provider for a public IP, or use a tunnel such as Cloudflare Tunnel or Tailscale.
- Blocked by your provider. Port 25 is blocked on most home connections to stop spam. Ports 80 and 443 are sometimes blocked too.
- Double NAT. If your provider's modem is also a router, you may need to forward the port on both, or put the modem in bridge mode.
Limitations
- We test TCP only. UDP ports, used by WireGuard and many games, cannot be tested reliably this way, because a closed UDP port and a working one often look the same.
- We test the address you are visiting from. If you are on a VPN, we test the VPN server instead.
- A port that is open from our server may still be blocked for some countries or networks by your own firewall rules.