How do I look up what a port number is used for?

Type the port number and the matching service, protocol, and description appear instantly.

Does it warn about risky ports?

Yes — high-risk ports are flagged with mitigation guidance.

Is it free and does it work without internet?

Yes — it is free and the dataset is searched entirely in your browser, even offline.

Port Number Reference — Free Online Port Number Reference

What service uses a given TCP or UDP port number?

Search AnyTool by port number or service name to find the matching TCP/UDP/SCTP service, its IANA status, description, and a security risk note. The full IANA dataset is searched instantly in your browser, and results export to CSV or JSON.

Search by port number or service name, both directions
Protocol (TCP/UDP/SCTP) and range (well-known/registered/dynamic) filters
Risk flags and mitigation tips for dangerous ports
CSV/JSON export and copy-to-clipboard per row
100% in-browser — instant search, works offline

What is

Network Port

A network port is a 16-bit number (0–65535) that identifies a specific service on a host. Well-known ports (0–1023) are reserved for common services like HTTP (80) and SSH (22); registered ports (1024–49151) and dynamic ports (49152–65535) cover everything else.

Developer Tools

Related terms

TCPUDPIANAWell-Known PortsFirewall

Frequently Asked Questions

Enter a port like 443 to jump to its services, or type a service name like ssh to find its ports. Results update live as you type, including protocol, IANA status, and the range classification (well-known, registered, or dynamic).

Dangerous ports such as 23 (Telnet), 445 (SMB), 3389 (RDP), and exposed database ports are annotated with risk flags and short mitigation tips, layered on top of the full IANA dataset.

The port dataset is shipped with the app and searched client-side, so lookups are instant and work offline after first load with no server round-trip, no signup, and no data sent anywhere.

Detailed Explanation

Methodology

How the Port Number Reference Works

AnyTool ships the IANA service-names-port-numbers dataset, pre-processed at build time into compact JSON and indexed as a Map of port to entries, then searched entirely in the browser. Lookups are bidirectional (port to service and service to port), support protocol filters (TCP/UDP/SCTP) and range filters (well-known, registered, dynamic), and accept range syntax like 8080-8090 and protocol syntax like :tcp. A curated overlay adds risk flags with mitigation tips for dangerous ports and real-world names IANA omits.

Full IANA breadth searched client-side
Bidirectional port and service lookup
Protocol and range filters with smart query syntax
Security risk flags and mitigation guidance
CSV/JSON export and deep-linkable URLs

Privacy & Security

Privacy and Offline Use

The dataset is self-hosted in the app and searched locally with no server round-trip and no runtime CDN, so lookups are instant and the tool works offline after first load as an installable PWA.

Port Number Reference: AnyTool vs typical tools
Capability	AnyTool	Typical tools
Dataset breadth	Full IANA	Often 50–200 ports
Processing location	In-browser	Often server-side
Security risk flags	Yes	Sometimes
CSV/JSON export	Yes	Rare
Works offline	Yes	No

Capabilities reflect the live AnyTool tool; competitor behavior varies by service.