Common Ports Lookup
Search well-known and registered network ports by number or service name. See the protocol and purpose of common TCP and UDP ports.
Last reviewed by the Radiatus Cloud team
Look up well-known TCP and UDP ports by number or service name.
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Look up well-known network ports
Network ports are numbered endpoints that identify specific services on a host, and many of them are standardised so that clients know where to connect. This reference lets you search the best-known and most commonly encountered TCP and UDP ports by number or by service name. Type 443 to confirm it is HTTPS, type "ssh" to find port 22, or type "tcp" to browse. The table shows the port number, the protocol it uses, and the service it is associated with.
The list covers the services administrators meet most often, from web, email and DNS to databases, remote desktop and VPNs.
Why knowing ports matters
Port numbers are central to firewall rules, troubleshooting and security. Opening the wrong port can expose a service, while blocking the right one can break an application. Recognising which service normally runs on a port helps you interpret scan results, read firewall logs, and configure access rules correctly.
Ports below 1024 are the well-known or system ports reserved for standard services, while higher numbers include registered and dynamic ports. This tool focuses on the common entries rather than the full registry. All searching happens locally in your browser.
Related tools
- Port Scanner — Check which common ports respond on a host and understand what each exposed service means. Scan only systems you are authorised to test.
- DNS Misconfiguration — Analyze DNS records (TXT, SPF) for security gaps.
- TLS Compat Tester — Check client-server compatibility for TLS versions.
- Firewall Rule Risk — Evaluate firewall rules for over-permissive exposure.
Frequently Asked Questions
What is a well-known port?
Well-known ports are numbers from 0 to 1023 reserved for standard services such as HTTP on 80 and HTTPS on 443, so clients know where to connect.
How do I search by service?
Type part of a service name, such as "mysql" or "vpn", and the tool lists every matching port along with its protocol and purpose.
What is the difference between TCP and UDP ports?
TCP provides reliable, ordered connections while UDP is connectionless and faster. Some services, like DNS, use both, which the table shows.
Is this the complete port registry?
No. It covers the ports administrators meet most often. The full registry maintained by IANA lists thousands of registered assignments.
Why does knowing ports help with security?
Recognising the service on a port helps you write correct firewall rules, spot unexpected open ports in scans, and understand what traffic logs are showing.
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How to Use
Type a port number or service name to find matching entries.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
Related Tools
Port Scanner
NetworkCheck which common ports respond on a host and understand what each exposed service means. Scan only systems you are authorised to test.
DNS Misconfiguration
NetworkAnalyze DNS records (TXT, SPF) for security gaps.
TLS Compat Tester
NetworkCheck client-server compatibility for TLS versions.