Test if a port is open on a specific hostname or IP address.

Use our free Open Port Checker to test external access to any port on your IP address. Great for checking server availability, firewalls, or NAT configurations.

If you're hosting a game server, configuring remote desktop, setting up FTP, or deploying web services, it’s important to make sure that your ports are actually open and accessible from the outside world. The Open Port Checker tool allows you to test whether a specific port on your public IP address is open, helping you confirm that your firewall, router, or NAT settings are configured correctly.

It’s fast, free, and ideal for system admins, gamers, developers, and network engineers.

What Is an Open Port?

A port is a virtual point where network connections start and end. Common examples include:

• Port 80 – HTTP (web traffic)
• Port 443 – HTTPS (secure web traffic)
• Port 21 – FTP
• Port 22 – SSH
• Port 3389 – Remote Desktop (RDP)
• Port 3306 – MySQL Database

An open port is one that can accept incoming connections. If a port is closed, external devices won’t be able to reach the service or application running behind it.

Why Use an Open Port Checker Tool?

Sometimes, even though a service is running, external connections fail due to:

• Closed ports on your firewall
• Incorrect router/NAT forwarding
• ISP port restrictions
• Cloud/VPS provider policies

The Open Port Checker helps you:

• Test if your server or application is publicly accessible
• Debug firewalls and network rules
• Confirm port forwarding settings on routers
• Troubleshoot remote access issues
• Ensure your services are reachable before going live

Features of the Open Port Checker Tool

• Public IP Testing: Verifies access from the outside, not just local LAN
• Custom Port Entry: Check any TCP port number
• Works on IPv4: Validates ports over standard internet protocol
• Real-Time Results: Know immediately if a port is open or closed
• Lightweight and Fast: No software or account required
• Safe to Use: Doesn’t attempt unauthorized actions — just tests connectivity

Example Use Cases

• Web Developers: Confirm that a local server is publicly accessible via port 80 or 443
• Gamers: Make sure game servers are reachable from outside networks
• Sysadmins: Test SSH (port 22), MySQL (port 3306), and custom services
• Home Users: Verify port forwarding rules for NAS, VPNs, or smart home devices
• IT Support: Diagnose remote access issues for clients

Common Troubleshooting Scenarios

• Port shows as closed?
  • Check firewall rules
  • Confirm service is running on that port
  • Verify router port forwarding settings
  • Ensure your ISP isn’t blocking that port

How to Use the Open Port Checker

1. Enter the public IP address or hostname you want to test
2. Enter the port number you want to check (e.g., 80, 443, 22)
3. Click "Check Port"
4. View the result — the tool will tell you if the port is open, closed, or filtered

For best results, ensure the service is running and your router/firewall allows incoming connections.

Whether you’re testing connectivity for a website, service, or remote desktop session, the Open Port Checker helps you verify that your ports are open and reachable from the public internet — so your applications work as intended.