Port Checker
Look up what a port number is used for, with its service name, protocol, and typical use, plus what a browser can and cannot reach on that port.
How to use
- Enter a port number, or switch to service name and type one such as https.
- Read the service, protocol, and typical use.
- Use a server-side check when you need to know whether a port is reachable.
A port checker here is a reference lookup, not a scanner. Browsers cannot open raw TCP connections, so no web page can tell you whether a remote port is open; this tool explains what a port is for and what reaching it takes.
Enter a port number or a service name.
A web page cannot test whether a port is open, because browsers block raw connections. This is a reference lookup.
Questions about port checker
- Can this tell me if a port is open?
- No. A page cannot scan ports, because browsers do not allow raw TCP connections and block most cross-origin probes. Reachability needs a server-side tool.
- Why is 8080 not in the standard registry?
- Ports in the thousands range are mostly assigned to common development frameworks rather than to an official standard. Treat those entries as conventions.
- What does a browser reach directly?
- Only the web protocols: HTTP, HTTPS, WebSocket, and WebSocket Secure, and only when the page is served from a page that is allowed to load them.
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