Common Port Number Lookup
Look up what service runs on a network port number, and the port for a service.
What's listening where
Network ports are numbered doorways, and many are conventionally tied to specific services — 80 and 443 for web, 22 for SSH, 25 for mail, 3306 for MySQL. This looks up what a given port is normally used for, and the usual port for a named service, so you can make sense of a firewall rule, a config, or a connection you are debugging.
Enter a port number or a service name to see the mapping.
Conventions, not rules
It is worth remembering these are conventions, not laws — a service can be configured to run on any port, and attackers sometimes hide services on unexpected ones. Still, the well-known port assignments are followed almost universally, which is exactly what makes them useful for reading configs and understanding what a system is doing. Knowing that 443 means HTTPS or 22 means SSH turns a cryptic port number in a log or rule into something meaningful.
Questions & answers
What are some common ports?
80 and 443 for web, 22 for SSH, 25 for mail, 3306 for MySQL — among many standardised assignments.
Must a service use its standard port?
No — it is a convention, and services can be configured on any port, but the standard assignments are followed almost universally.
Is anything uploaded?
No. It is a reference that runs in your browser.