What are well-known ports?

Well-known ports are the range 0–1023 reserved by IANA for core internet services such as HTTP (80), HTTPS (443), SSH (22), and DNS (53). Ports 1024–49151 are registered ports for application use, and 49152–65535 are dynamic/private ports.

Does this tool actually scan my network?

No. This is a pure reference tool — it lists static information about port assignments. It performs no network scanning, no socket connections, and makes no outbound requests of any kind.

Why are some ports listed for both TCP and UDP?

TCP and UDP are independent transport protocols. Some services (like DNS on port 53) listen on the same port number for both protocols simultaneously, so they appear in both TCP and UDP rows.

Where does this data come from?

Port assignments are based on the IANA Service Name and Transport Protocol Port Number Registry, which is the authoritative source for standardized port assignments.

How do I copy a port number?

Click anywhere on a table row to copy that port number to your clipboard. A brief confirmation message will appear.

Why does port 0 appear?

Port 0 is reserved by IANA and is technically invalid for actual use. It sometimes appears in network diagnostics tools as a placeholder or in firewall rule output, so it is included for completeness.

Common Ports Reference

Name: Common Ports Reference
Availability: InStock
Author: Nham Vu

Search and browse all well-known TCP/UDP ports (0–1023) with service names, protocols, and plain-English descriptions.

Showing all ports

Port	Proto	Service	Description

Port copied!

Summary

Search and browse all well-known TCP/UDP ports (0–1023) with service names, protocols, and plain-English descriptions.

How it works

The full list of 70+ well-known ports is embedded in the page as a JavaScript dataset.
Type any port number, service name, or keyword into the search box.
Results filter in real time as you type — no page reload needed.
Click any row to copy the port number to your clipboard.
Use the Protocol filter (All / TCP / UDP) to narrow results further.

Use cases

Quickly look up what service runs on an unfamiliar port number.
Verify firewall rule port ranges during network configuration.
Check whether a custom app port conflicts with a well-known service.
Study for networking certifications (CompTIA Network+, CCNA).
Identify suspicious listening ports on a server.
Reference during penetration testing reconnaissance notes.
Confirm TCP vs. UDP for a service when writing iptables rules.
Teaching aid for network fundamentals courses.

Frequently Asked Questions

Last updated: 2026-06-09 · Reviewed by Nham Vu