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Port Checker Reference

Common network ports reference with protocol info and descriptions.

⚠️ Browser limitation: Browsers cannot directly test remote ports for security reasons. This is a reference tool. To actually check ports, use telnet host port, nc -zv host port, or Test-NetConnection (PowerShell).
PortProtocolServiceDescription

Frequently Asked Questions

What is a network port?
A port is a number (0-65535) identifying a specific process or service. Ports 0-1023 are well-known, 1024-49151 are registered, and 49152-65535 are dynamic/private.
How do I check if a port is open?
Use telnet host port, nc -zv host port, or PowerShell's Test-NetConnection -ComputerName host -Port port.
What's the difference between TCP and UDP?
TCP is connection-oriented with guaranteed delivery. UDP is connectionless, faster but without delivery guarantees. TCP is used for web, email; UDP for DNS, streaming, gaming.