TCP/UDP Port Lookup

TCP/UDP Port Lookup: Core Features & Principles

When you encounter an unknown port or need to confirm the standard service of a specific port, you often need to quickly look up its official definition. This tool is an online lookup utility based on the IANA (Internet Assigned Numbers Authority) standard port database. It returns the corresponding network service name, protocol, and standard functional description based on the port number you enter. It primarily processes port numbers, which are integers between 0 and 65535 used to identify different network application processes on a host.

Why Choose Our TCP/UDP Port Lookup?

• Authoritative & Comprehensive Data: The data source is based on IANA standards, covering well-known ports (0-1023), registered ports (1024-49151), and some dynamic/private ports, making the query results highly reliable.
• Clear Protocol Distinction: Supports specifying a "/tcp" or "/udp" protocol suffix during input (e.g., "53/udp"), or performing a general query without specifying a protocol. The results clearly display the association between the port and the protocol.
• Clear & Intuitive Results: Query results are presented in a table format, containing three columns: "Port/Protocol", "Service Name", and "Description". The information is clear at a glance, making it easy to understand and record quickly.

How to Use This Tool

1. Enter a port number between 1 and 65535 in the search box (e.g., 80, 3306).
2. (Optional) For a more precise search, you can append "/tcp" or "/udp" to the port number (e.g., 53/udp).
3. Click the search button or press Enter, and the matching port service information will be displayed immediately below.

Frequently Asked Questions (FAQ)

Q: What is port 80 used for?
Port 80 is the standard port for HTTP (Hypertext Transfer Protocol) services, used to provide web browsing services.

Q: Why does the "Port/Protocol" column in the results sometimes show only a number, and sometimes show "number/tcp"? What does this mean?
This indicates the protocol binding status of the port when registered with IANA. Showing only a number (e.g., "443") usually means the port number is associated with both TCP and UDP protocols, or is universally applicable by default. Showing "number/tcp" (e.g., "22/tcp") means the service is explicitly registered in the standard to use only the TCP protocol. Our tool accurately reflects these differences in registration information.

Important Notes

This tool is a static reference library for port information, not a real-time port scanner. It cannot detect the actual open status of ports on your or a remote host. Port usage may vary due to private protocols or specific application configurations; the definitions provided here are the most common or official ones. When performing network configuration or security audits, please be sure to verify against your actual environment.

Technical Notes & Usage Tips

For network administrators and developers, understanding port classifications helps troubleshoot issues efficiently. Well-known ports (0-1023) typically require system privileges to bind, such as SSH (22/tcp) and HTTPS (443/tcp). Registered ports (1024-49151) are used for user-level processes, such as MySQL (3306/tcp) and Redis (6379/tcp). Dynamic/private ports (49152-65535) are usually used for temporary connections. A typical query example is entering "53/udp", which will return the service name "domain" and the description "DNS (Domain Name System)", clarifying that DNS queries typically use the UDP protocol on port 53.