Open Port Checker
Verify if a port is successfully forwarded through your router.
How to Use the Port Checker
An open port checker is a network utility used to verify if your computer or server can be reached from the outside internet on a specific port. Verify if you set up port forwarding correctly.
Find the Port Number
Determine which port your application uses. Common examples include port 80 for HTTP web servers, 25565 for Minecraft, and 3389 for Remote Desktop Protocol (RDP).
Check Your IP
This tool automatically detects your current public IP address (the IP address your router exposes to the world).
Run the Test
Enter the port number in the input box above and click 'Check Port'. We will attempt to establish a connection to your public IP on that port.
Analyze the Result
If the tool reports "Open", your port forwarding is working perfectly. If it reports "Closed", your router's firewall is blocking the connection.
Common Reasons for Closed Ports
If you forwarded the port on your router but this tool still says it's closed, check the following:
- The server isn't running: Port forwarding only works if the target application (like the game server) is currently running and actively listening on that port.
- Windows Firewall: Sometimes your router allows the traffic through, but your computer's local operating system firewall blocks it. Ensure you have added an exception in Windows Defender Firewall.
- CGNAT (Carrier-Grade NAT): Many modern ISPs use CGNAT to conserve IPv4 addresses. If your ISP uses CGNAT, standard port forwarding will not work without requesting a static IP.