Port Checker — Common Network Ports Reference

Search and explore common TCP/UDP network ports. Learn which ports popular services use and how to check if a port is open on your computer or router.

What Is a Network Port?

A network port is a logical endpoint for communication in a computer network. Ports allow a single IP address to handle multiple simultaneous services. Think of an IP address as a building's street address and ports as individual apartment numbers within that building.

Port numbers range from 0 to 65535. They are divided into three categories:

• Well-Known Ports (0-1023): Reserved for standard services like HTTP (80), HTTPS (443), and SSH (22). These require administrator privileges to bind on most operating systems.
• Registered Ports (1024-49151): Assigned by IANA for specific applications like MySQL (3306) and RDP (3389).
• Dynamic/Private Ports (49152-65535): Used temporarily by client applications for outbound connections.

How to Check If a Port Is Open

You can check if a port is open or closed on your computer or remote server using built-in command-line tools. Below are instructions for each platform.

Windows

Open Command Prompt or PowerShell and run:

netstat -an | findstr :80
Test-NetConnection -ComputerName 192.168.1.1 -Port 443

macOS / Linux

Open Terminal and run:

netstat -an | grep :80
nc -zv 192.168.1.1 443
nmap -p 80,443 192.168.1.1

Using Telnet

telnet 192.168.1.1 80

If the connection succeeds, the port is open. If it times out or is refused, the port is closed or filtered.

Port Forwarding

Port forwarding redirects incoming traffic on a specific port from your router to a device on your local network. This is necessary for hosting game servers, remote desktop access, security cameras, and other services that need to be accessible from the internet.

For a detailed guide on setting up port forwarding on your router, see our Port Forwarding Setup Guide.

Security Considerations

Open ports can be entry points for attackers. Follow these best practices to keep your network secure:

• Close unused ports on your router and firewall
• Never expose database ports (3306, 5432, 1433) to the public internet
• Use SSH (port 22) instead of Telnet (port 23) for remote access
• Replace FTP (ports 20/21) with SFTP or SCP which run over SSH
• Keep firmware and software updated to patch known port-related vulnerabilities
• Use a VPN instead of opening RDP (3389) to the internet

TCP vs UDP

Feature	TCP	UDP
Connection	Connection-oriented (3-way handshake)	Connectionless
Reliability	Guaranteed delivery with retransmission	No guarantee, best-effort
Speed	Slower due to overhead	Faster, lower latency
Use Cases	Web browsing, email, file transfer	DNS queries, streaming, gaming
Header Size	20-60 bytes	8 bytes

Video Tutorial

Related Tools and Guides

• How to Set Up Port Forwarding
• Subnet Calculator
• What Is My IP Address?
• IANA Service Name and Port Number Registry

Frequently Asked Questions

What is port 443 used for?

Port 443 is the default port for HTTPS, which is HTTP encrypted with TLS/SSL. Every secure website you visit in your browser uses port 443. It is essential for online banking, shopping, and any site that handles sensitive data.

Is it safe to open port 80?

Port 80 is used for unencrypted HTTP traffic. Opening it on your router is necessary if you host a web server, but you should also configure HTTPS on port 443 and redirect HTTP traffic to HTTPS. Avoid sending sensitive data over port 80.

How do I close a port on my router?

Log in to your router's admin panel (usually at 192.168.1.1 or 192.168.0.1), navigate to port forwarding or firewall settings, and remove any rules forwarding that port. The port will then be blocked by default.

What ports do games use?

Common gaming ports vary by platform. PlayStation Network uses ports 80, 443, 3478-3480. Xbox Live uses ports 53, 80, 88, 500, 3074, 3544. Most PC games use specific ports listed in their documentation. Check your game's support page for exact port requirements.