Port Reference
Search well-known port numbers.
Sources and selection
The authoritative registry for port numbers is the IANA Service Name and Transport Protocol Port Number Registry. This table is not a copy of that registry (which runs to thousands of entries). It is a selection of the ports you actually meet when running servers, configuring firewalls, and debugging, with our own practical notes and security caveats added to each. Ports where registration and real-world use diverge (8080, 3000) are included on practical grounds. Check the upstream registry below when you need the exact registration record.
What the Port Number Reference Is
A TCP/UDP port number is a 16-bit identifier that distinguishes the many services running on a single host. Among them, the well-known ports 0 to 1023 are assigned by convention to standard services such as HTTP (80), HTTPS (443), and SSH (22), so when writing firewall rules or diagnosing connection problems you often need to quickly confirm which port maps to which service.
This tool provides a table of common well-known ports plus service ports you meet in practice, such as databases, message queues, and development servers. Each entry lists the port number, protocol (TCP/UDP), service name, and a short description so you can scan them at a glance.
Searching and filtering run entirely in your browser and send no data anywhere. It works as an offline cheat sheet you can consult instantly even without a network connection.
How to Use
- Type the port number or service name you are looking for into the search box, for example 443, ssh, or mysql.
- The table filters as you type, leaving only the rows whose port, protocol, service, or description match. Searching by number, service name, or description all work.
- Clear the search to show the full list again. Find the port row you need and use it as a reference for your firewall rules or documentation.
Frequently Asked Questions
- What is the difference between well-known and registered ports?
- Ports 0 to 1023 are well-known (system) ports reserved for standard services like HTTP and SSH, and binding to them usually requires administrator privileges. Ports 1024 to 49151 are registered ports assigned to specific applications, such as MySQL (3306), and 49152 to 65535 are the dynamic or ephemeral ports.
- Can the same port number be used for both TCP and UDP?
- Yes. The TCP and UDP port spaces are independent, so the same number can serve different purposes under each protocol. Some services, like DNS (53), actually use both TCP and UDP, which is why the table shows the protocol alongside each entry.
- Why are ports like 3000 or 8080 so common in development?
- They are not reserved standard ports but sit in the unregistered higher range, so you can bind to them freely without administrator privileges. That is why local development servers and proxies conventionally default to 3000, 8080, 8443, and similar.