Port Number Reference

How to use it

1. Type the number in whatever shape you have it. 8080, port 8080, :8080, tcp/8080 and 08080 all reach the same lookup, and pressing / jumps to the field.
2. Read every row, not the first one. One number can carry a TCP row, a UDP row and an SCTP row with different service names and different descriptions, and each row shows its own registry status.
3. Type a range such as 1024-49151 to have it classified instead of looked up. That answer costs no download: it is arithmetic over the three ranges RFC 6335 defines.
4. Have a word instead of a number? The table below filters as you type with nothing to fetch, and searching the whole registry is a separate button that prints its download size first.

Type a port number and this page prints every row the IANA service registry lists against it: each transport, service name, description and status, rather than one blended answer. The snapshot is the registry as retrieved on 2026-08-14 — 14,531 rows, 13,463 of them tied to a number. The lookup runs in this browser, and it cannot tell you whether a port is open anywhere.

How it works

A port number is not the registry's key. IANA files each entry under the number plus a transport protocol plus a service name, so a number reappears once per transport and again for every extra name registered on it. The snapshot holds 6,242 TCP rows, 6,234 UDP rows, 91 SCTP rows and 10 DCCP rows — which is why 443 answers with three and 80 with seven.

RFC 6335 §6 cuts the 65,536 numbers into three. 0-1023 is the System range, which Unix-like systems have historically let only root bind. 1024-49151 is the User range, registered on request and bindable by anyone. 49152-65535 is the Dynamic range, which IANA assigns to nothing at all — 49151 is the highest number in this snapshot, and the operating system draws from above it for outgoing connections.

An assignment is a name reservation, not enforcement. No kernel consults this registry: any program with the right privileges may bind any free number, and RFC 7605 spends its length asking implementers to use assigned numbers rather than describing anything that would make them. A row tells you what a number was registered for, never what is listening on it.

That is why a second, separately labelled list sits below. IANA registers 3000 as hbci and remoteware-cl, and no row anywhere mentions a development server; 5173 has no row of its own and falls inside a block marked Unassigned. The real-world entries are ours, each linked to the project's own documentation, and none is merged into a registry row.

The registry itself is too big to print. Its 13,463 numbered rows are packed into 7 files totalling 372,064 bytes, fetched only when a lookup needs one: the ranges are disjoint, so a number costs exactly one file and anything above 49151 costs none. In the page instead is a 216-port table you can read and link to with JavaScript switched off.

Examples

443

443 · System port (0-1023) · The registry lists 3 rows for this port. · tcp https http protocol over TLS/SSL · udp https http protocol over TLS/SSL · sctp https HTTPS

80

80 · System port (0-1023) · The registry lists 7 rows for this port. · tcp http World Wide Web HTTP · tcp www World Wide Web HTTP · tcp www-http World Wide Web HTTP · udp http World Wide Web HTTP · udp www World Wide Web HTTP · udp www-http World Wide Web HTTP · sctp http HTTP

8080

8080 · User port (1024-49151) · The registry lists 2 rows for this port. · tcp http-alt HTTP Alternate (see port 80) · udp http-alt HTTP Alternate (see port 80)

3000

3000 · User port (1024-49151) · The registry lists 4 rows for this port. · tcp hbci HBCI · tcp remoteware-cl RemoteWare Client · udp hbci HBCI · udp remoteware-cl RemoteWare Client

49152

49152 · Dynamic port (49152-65535) · IANA has not assigned port 49152 to any service.

1024-49151

1024-49151 · User port (1024-49151) · 1024-49151 is the User range: IANA registers a number here on request, and any process may bind one without special privileges.

Every example on this page is executed against the same engine that powers the tool, on every build.

Common errors

65536 is not a port number — a port is a whole number from 0 to 65535.

A port field is 16 bits wide, so 65535 is the last one that exists. A negative number lands here too, since the field has no sign to spend.

That query is 150 characters long, which is past what this field reads.

The field reads the first 128 characters and refuses anything longer rather than quietly cutting it down, and the refusal prints the length you actually pasted.

80.5 isn't a port number or a range — try 8080 or 1024-49151.

Numeric-looking input that is neither a whole port nor a two-ended range. Rather than guess between a typo and a name search, the page quotes the token back and names the two shapes it reads.

That part of the registry couldn't be downloaded — the range classes, the table below and the real-world list still work.

Shown when one registry file fails to arrive, usually a dropped connection. It is a notice, not an error page: everything the page already had keeps answering.

Keyboard shortcuts

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Focus the port field