Port Number Lookup
Search IANA service names and transport ports by number, range or keyword.
Use the registry as a reference
Enter a port such as 53, an inclusive range such as 8000-8010, or a keyword from a service name, description, reference or assignment note. Empty input browses the registry. Protocol filters retain protocol-independent entries. Pagination applies after filtering; the export contains the current page, with the total count and page information in JSON.
Snapshot and interpretation
The bundled IANA registry was updated on 2026-10-22 and retrieved on 2026-10-25. It contains all 14,542 CSV records, including ranges, reserved or unassigned rows, service-name-only entries and TCP, UDP, SCTP and DCCP assignments. Contacts are omitted. This page does not make a live registry request.
Ports 0-1023 are system ports, 1024-49151 user ports, and 49152-65535 dynamic/private ports. A registered service does not prove that traffic on that port belongs to it or that a port is open. This tool performs no scan. A missing snapshot record is not proof that a port is available.
Limits and exports
Use port numbers from 0 to 65535 and ascending ranges. Keyword length is limited to 200 characters; a page returns 1-1000 records. A page outside the filtered result range is rejected. JSON preserves source descriptions and notes; CSV uses CRLF and protects formula-like cells. The table shows the service, range, protocol and description.
Questions & answers
Does this test whether a port is open?
No. It is an offline registry lookup. Use an authorized network diagnostic tool to test a service.
Why can there be several entries for one number?
Different transport protocols and registry assignments can share a number. Ranges and protocol-independent records can also match.
Other Languages
References
How we make sure
We check this tool with the automated test suites linked below. Example checks are shown in their original language.
- Verification method
- Check queries, source fields, pagination and totals for fixed extension/MIME or port/transport records.
- Comparison reference
- mime-types uses mime-db data; port-reference uses the project’s IANA registry snapshot and provenance.
- Verification scope
- This verifies lookup behavior, not perpetual freshness or the service actually running on a peer.
Test source and cases (select a file to read it)
-
live-network-tools.test.js
- IANA lookup distinguishes transport and preserves authoritative DNS records and provenance
- Port ranges, full registry browsing, keywords and pagination preserve complete filtered totals
- Port classifications and CSV do not imply scans or service identity
These checks cover the listed examples and boundaries, not every possible input. Round trips and checks using the same library are not independent verification.