Open Ports Test

Click Run a port check to confirm if your services are reachable.

Port reachability

Open Ports Test

Check if common ports are reachable on your public IP or another host.

Ready

Your public IP--

Remote addressPort number

Results will appear here after a scan.

This test uses a server-side TCP check to see if a port is reachable.

Common ports

Why run an open ports test

An open ports test checks whether specific service ports on a public IP are reachable from the internet. It is useful when setting up port forwarding, remote access, or troubleshooting firewall rules.

How the test runs

The tool sends a TCP connection attempt from a remote server to the target IP and port. If the connection responds, the port is reported as open, and the test ends when you leave the page.

How to interpret results

An open result means the port responded to the connection attempt, while a closed result means it did not. Firewalls, missing port forwarding, or a stopped service can make an open service appear closed. Use the result to confirm external reachability after network changes.

Open indicates the port responded to a TCP attempt.
Closed can be caused by firewall rules or inactive services.
Results depend on public IP and routing configuration.

This test checks TCP ports only and cannot scan private networks or validate internal firewall rules.

Frequently Asked Questions

What is an open ports test used for?

An open ports test checks whether specific ports on a public IP are reachable from the internet. It helps verify port forwarding and firewall rules.

How does the open ports test work?

The tool sends a TCP connection attempt from a remote server to the target IP and port. If it receives a response, the port is reported as open.

Can I scan any host with the open ports test?

For safety, the test accepts only public IPv4 addresses. It will not scan private or local network addresses.

Does the open ports test check UDP?

No, this test checks TCP ports only. UDP requires different methods and is not covered here.

Why does an open port show as closed?

Firewalls, missing port forwarding, or a stopped service can make a port appear closed. Some services also block scans, which can look closed.

Do I need port forwarding for the open ports test?

If the service is behind a router, you usually need port forwarding for it to be reachable. Without forwarding, the port often appears closed.

Is the open ports test safe to use?

The test only attempts standard TCP connections to the host you provide. It does not access your device or store scan results.

Why do open ports test results differ from other scanners?

Results can differ based on scan location, timing, and port lists. This tool focuses on common ports and manual checks.

Can this open ports test scan my local network?

No, it only tests public IP addresses from the internet. It cannot scan private network ranges.

What can the open ports test not do?

It cannot scan your entire private network or validate internal firewall rules. It only tests the specific public IP and ports you request.

Open ports test not working?

If the host is not public, the test will fail. Double-check the IP address and ensure the service is reachable from the internet.

Does the open ports test store results?

No, it only reports reachability for the ports you test. Results are not stored or saved.