Open Port Checker for Your Public IP
Check if a TCP port is open on your own public IP — port forward checker
* WireGuard and most game voice traffic use UDP, which this TCP test cannot check.
Check if a port is open from the internet
You've set up port forwarding for a Minecraft server, Plex, a home web server or remote desktop, and friends still can't connect. The question is whether the port is reachable from outside your network — something you can't test from inside it, because connections from your own LAN never cross the router the same way. This open port checker answers it from the outside: our server tries to open a TCP connection to the port you choose on your public IP address and reports one of three results.
Open means the TCP handshake completed: something is listening and the path through your router and firewall works. Closed means our connection reached your IP but was actively refused — typically the router has no forwarding rule for that port, or the forward points at a device where nothing is listening. Filtered means no answer arrived within three seconds: a firewall silently dropped the packets, the ISP blocks the port, or nothing routes there at all.
Pick a port from the quick list — 22 (SSH), 80 and 443 (web), 3389 (RDP), 8080, 25565 (Minecraft Java), 32400 (Plex) and others — or type any port from 1 to 65535. Each request tests one port. The check is TCP only; services that use UDP, such as WireGuard, many game voice chats and Minecraft Bedrock, can't be confirmed this way. The result isn't stored.
Why this port checker only tests your own IP
Many port checker tools let you type any IP address. This one deliberately doesn't. It always tests the public IP your request comes from, read from the forwarding headers our CDN adds, and there is no field for another host. That design means the tool can't be turned into a free port scanner aimed at someone else's network, which would be both abusive and, in many places, unlawful. It's also rate-limited to 10 checks per minute per IP for the same reason.
The trade-off is that the device you check from must share the public IP of the network you're testing — run it from a phone or computer on the same Wi-Fi as the server, not on mobile data. If the page shows an address that isn't yours, you're probably connected through a VPN or a proxy; disconnect it and reload. If your address falls in 100.64.0.0/10, your ISP uses carrier-grade NAT, which means your router doesn't own a public IPv4 address and inbound port forwarding cannot work without the ISP's help — ask them for a public IP, use IPv6 if they provide it, or use a tunnelling service.
When a port forward checker says closed or filtered, work through the usual causes: the forwarding rule points at the wrong local IP (give the server a static DHCP lease), the service is bound only to localhost, the operating system's firewall on the server blocks the port (Windows Defender Firewall, ufw, firewalld), the router has two layers of NAT (an ISP modem in front of your own router), or the ISP blocks common ports like 25 and 80 on residential lines. Fix one thing at a time and re-check.
How to use the Open Port Checker for Your Public IP tool
- 1
Connect from the network you want to test
Use a device on the same network as the server, with any VPN switched off; your public IP is shown at the top.
- 2
Choose a port
Click a common port such as 25565, 32400 or 3389, or type any TCP port from 1 to 65535.
- 3
Run the check
Our server attempts a TCP connection to your public IP on that port, with a three-second timeout.
- 4
Interpret the result
Open means reachable; closed means refused (no forward or nothing listening); filtered means dropped by a firewall or ISP.
Frequently asked questions
Can I check a port on another IP address?
No. The tool only tests the public IP your own request comes from, so it can't be used to scan other people's networks. Run it from a device on the network you want to test.
What's the difference between closed and filtered?
Closed means the connection reached your IP and was refused, usually because there's no port forward or nothing is listening. Filtered means there was no reply at all — typically a firewall dropping packets or an ISP block.
Can it test UDP ports?
No. Only TCP connections can be confirmed this way. UDP services such as WireGuard or Minecraft Bedrock need a client-side test from the game or app itself.
My port forward is set up but shows closed — why?
Common causes are a forward pointing at the wrong local IP, the service listening only on localhost, the server's own firewall, double NAT, or the ISP's carrier-grade NAT. Fix and retest one at a time.
Does it test IPv6?
If your browser reaches us over IPv6, that address is tested. Our server's IPv6 reachability depends on its network; an unreachable result on IPv6 may reflect that rather than your firewall.
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