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Open Port Checker
Check whether a TCP port is reachable on your public IP. Handy for port forwarding and game servers.
About Port Checker
A port checker tests whether a TCP port on your public IP address accepts connections from the internet. Use it after setting up port forwarding for a game server, Plex, a security camera, SSH or remote desktop. The test runs from Cloudflare's network against your own IP only, so it reflects what the outside world actually sees.
Frequently asked questions
How do I check if a port is open?
Enter the port number above and press Check port. The test connects to your public IP address from the internet and reports open, closed or no response. To check from your own computer instead, use netstat or Test-NetConnection on Windows, or ss and nc on macOS and Linux.
Why does my port show as closed when my server is running?
Three things usually block it: the service is not listening on that port, your computer's firewall blocks it, or your router is not forwarding the port to your device. Also check that your provider does not use carrier-grade NAT, which prevents inbound connections entirely.
Is it safe to open a port?
Opening a port exposes whatever is listening behind it to the whole internet. Only forward ports for software you keep updated, use strong authentication, and close ports you no longer need. Prefer a VPN or a tunnel for remote access to private services.