What are well-known ports?

Well-known ports are numbers 0–1023, assigned by IANA to core internet services. Examples: 80 (HTTP), 443 (HTTPS), 22 (SSH), 25 (SMTP). They typically require root/administrator privileges to bind on Unix-like systems.

What is the difference between TCP and UDP?

TCP (Transmission Control Protocol) provides reliable, ordered delivery and is used by services like HTTP, SSH, and FTP. UDP (User Datagram Protocol) is connectionless and faster, used by DNS, DHCP, VoIP, and streaming services.

Why does a port show both TCP and UDP?

Some services are registered for both transport protocols. DNS (port 53) is the most common example — it uses UDP for standard queries and TCP for zone transfers or large responses.

What are registered ports?

Registered ports are numbers 1024–49151, assigned by IANA to specific applications and services upon request. Common examples include 3306 (MySQL), 5432 (PostgreSQL), 6379 (Redis), and 8080 (HTTP Alternate).

What are dynamic or private ports?

Ports 49152–65535 are dynamic (ephemeral) ports not assigned by IANA. Operating systems use them as temporary source ports for outbound connections. No IANA service assignments exist in this range.

Is this data up to date?

The tool uses the IANA Service Name and Transport Protocol Port Number Registry as its reference. The built-in database covers all well-known ports and the most commonly used registered ports.

Port Number Lookup

Enter a port from 0–65535 to see matching common TCP/UDP services and its IANA range. An assignment does not prove that the port is open on a device.

Port Lookup

Port number (0 – 65535)

Protocol filter

Search by service name

Common ports

Enter a port number or service name to search.

Searches common assignments and classifies every valid port from 0–65535.

Port	Proto	Service	Description	Status

System ports · 0–1023

Also called well-known ports; assignments are controlled most strictly.

User ports · 1024–49151

Also called registered ports; many applications request assignments here.

Dynamic/private · 49152–65535

Not assigned by IANA; commonly used for temporary or private endpoints.

Lookup ≠ port scan. This page maps numbers to known assignments locally in your browser. It does not contact an IP address, test a firewall, or determine whether a port is open. Registry reference: IANA Service Name and Transport Protocol Port Number Registry.

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Summary

Enter a port from 0–65535 to see matching common TCP/UDP services and its IANA range. An assignment does not prove that the port is open on a device.

How it works

Enter a port number (0–65535) in the search box.
The tool instantly filters its curated common-port reference.
Results show matching service names, protocol, description, and assignment label.
If no common service is listed, the tool still identifies the number’s IANA range without inventing an assignment.
Use the protocol filter to narrow results to TCP-only or UDP-only.
Click "Copy" on any row to copy the port number to your clipboard.

Use cases

Identify an unfamiliar port seen in firewall logs or a network scan.
Verify which service should be listening on a given port during server setup.
Check IANA status before registering a port for a new application.
Quickly reference common ports (80, 443, 22, 3306, etc.) without memorizing them.
Audit open ports on a machine and map each one to a known service.
Prepare for networking certifications by studying port assignments.

Frequently Asked Questions

Last updated: 2026-09-22 · Reviewed by Nham Vu