Open Port Checker
Check whether a TCP port is open and reachable on a public IP address or host.
Common ports
Continue your work
- What Is My IP Address — Find your public IP address.
- Online Ping Test — Measure latency to the same host.
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Clear instructions
Find steps, examples and limitations below.
Use online
Open the tool in a supported web browser.
Free to use
No sign-up required. Tool-specific limits may apply.
How to use the Open Port Checker
Check whether a TCP port is open and reachable on a public IP address or host.
- 1 Enter a domain or public IP address, or click Use my IP to test your own connection.
- 2 Enter a port number or click one of the common ports.
- 3 Click Check port. Open means something accepted the connection; closed or timed out means it is blocked or nothing is listening.
Example and practical tips
After forwarding port 25565 on your router for a Minecraft server, click Use my IP and the 25565 button. If it shows closed, check the router rule, the server’s firewall and that the server is running.
Frequently asked questions
Why is my port closed even though I forwarded it?
Common causes are a firewall on the computer, the service not running, the wrong internal IP in the rule, or an ISP that uses carrier-grade NAT so you have no public IP.
Can I check private IP addresses?
No. The check runs from our server over the internet, so only public addresses can be tested.
Report an issue
Something broken or not quite right? Tell us and we will look into it.