List of TCP and UDP port numbers
TCP and UDP port numbers are how network applications find and talk to each other. Both protocols use port numbers to identify services on a device, and a single port is used for both directions of traffic.
Who assigns ports
- The Internet Assigned Numbers Authority (IANA) manages official port assignments.
- Many ports have unofficial uses in practice, and some official assignments reference protocols that are no longer common.
Port ranges
- 0 to 1023: well-known (system) ports. Used by core services. On Unix-like systems, binding to these ports usually requires superuser privileges.
- 1024 to 49151: registered ports. IANA assigns these for specific services after a request. These ports can typically be used without elevated privileges.
- 49152 to 65535: dynamic or private ports. Not assigned by IANA; used for private, temporary, or ephemeral ports.
In short, port numbers help identify which service to reach, with different ranges serving different purposes.
This page was last edited on 2 February 2026, at 06:35 (CET).