Port Number Lookup
Find the service behind a TCP/UDP port.
How to use
- 1 Type a port number between 0 and 65535 into the input.
- 2 Read the matched service name, protocol and description.
- 3 Note the port range badge: well-known, registered or dynamic.
- 4 Try common dev ports like 3000, 5173 or 8080 to confirm conflicts.
About Port Number Lookup
The Port Number Lookup tool tells you what a TCP or UDP port number is commonly used for.
Type a number such as 22, 443 or 5432 and it returns the registered service name, the usual protocol, a short description, and which range the port falls into — well-known (0 to 1023), registered (1024 to 49151) or dynamic/ephemeral (49152 to 65535).
It is the fast answer to the everyday questions: which port is Postgres on, what is listening on 6379, or is this number even a valid port.
The data set is a curated, offline subset of the IANA assignments focused on the services developers and sysadmins actually meet — web, mail, databases, caches, directory services, remote access and the popular local dev-server ports like 3000 and 5173.
When a number has no common assignment in the list, the tool still validates it and classifies its range, so you always learn something useful.
Because the lookup table ships with the page, there are no network calls: nothing you type leaves your browser, and the tool works entirely offline once loaded.
That makes it quick, private and dependable even on a locked-down network.
FAQ
What are the three port ranges?
Well-known ports are 0–1023, registered ports are 1024–49151, and dynamic or ephemeral ports are 49152–65535.
Why does my port show no service?
The tool ships a curated list of common services. Unlisted ports are still validated and classified by range, but have no registered name here.