Port Number Lookup
A reference table of well-known TCP/UDP port numbers and services. Search by port number or service name. All processing happens inside your browser.
| Port | Protocol | Service | Description |
|---|
Frequently asked questions
What are well-known ports?
They are ports in the 0-1023 range assigned to standard services such as HTTP (80), HTTPS (443), and SSH (22). They are managed by IANA.
Can I search by port number or service name?
Yes. Enter a port number (e.g. 443) or service name (e.g. https) in the search box to filter and show only matching rows.
Does it check whether a port is actually open?
No. This tool is a reference table of standard port numbers and does not test whether a port is open on any particular server.
Practical example and verification criteria
Port Number Lookup: First determine whether this page only calculates a format in the browser or the Tool Web server performs a DNS, port, or public-IP lookup. Do not mix a protocol or path into a hostname. Enter IP, MAC, and port values with the separators and ranges requested by the page, and confirm you are authorized to query the target.
Port Number Lookup: For a quick check, start with 443 → HTTPS as a small input whose result relationship you can verify directly. Confirm that the input summary, units, and options match your intent before applying the tool to real values or a copy of the source; this reduces setup mistakes.
Port Number Lookup: DNS caches, firewalls, NAT, proxies, and the lookup server's location can make results differ from observations on your device or another network. Recheck the same target with operating-system commands or an authorized management console. Location data is approximate, and a port response alone cannot establish that a service is secure.
Port Number Lookup · Work record: For real work, record the input conditions, selected options, and result together. Do not assume the same state will remain after a refresh or device change. Preserve important results separately using copy, download, a screenshot, or another method the page supports, then reopen them in the target environment.
Port Number Lookup · Error check: If an error or unexpected result appears, reduce the input, run again with default options, and then change one condition at a time. Recording error messages and boundary values helps distinguish format issues, unsupported cases, and browser resource limits, and prevents an empty result from being mistaken for success.
Port Number Lookup · Scope of use: Check the page guidance for browser processing versus server lookup, storage location, and supported scope. Use sensitive source material or secrets only when strictly necessary. High-impact work such as legal, financial, or medical decisions or changes to an operational system requires current authoritative information and a separate verification process.