📌 Use Cases

Ports are the entry and exit points of network services. This tool queries the protocol, service, and security risks behind TCP / UDP ports, helping ops quickly identify open ports and troubleshoot firewall and port conflicts — ideal for server hardening and troubleshooting.

📖 Learn More About port lookup

Why You Need It

Identify what a listening port is for.
Spot open ports that should be closed.
Troubleshoot firewall and service conflicts.

How It Works

It maps a TCP/UDP port number to its well-known service, protocol, and typical security notes.

A Quick Example

Enter '443', see it is HTTPS, and confirm whether it should be exposed.

Common Mistakes

Assuming a port number defines the service (it is a convention).
Leaving unnecessary ports open to the internet.
Confusing TCP and UDP behavior.

About the free online Port Lookup

Looking for a free online Port Lookup? Ports are the entry and exit points of network services. This tool queries the protocol, service, and security risks behind TCP / UDP ports, helping ops quickly identify open ports and troubleshoot firewall and port conflicts — ideal for server hardening and troubleshooting. This tool is completely free and requires no registration — every operation runs locally in your browser, your data is never uploaded to any server, and you can use it anytime just by opening the page.

🔌 Port Lookup

Search TCP/UDP port numbers, protocols, services, and security risks. Click a port number to copy it.

Port	Protocol	Service	Category	Security	Description

🔒 All data is stored locally in this page. No queries are sent to any server.

📋 How to Use

Type a port number, service name, or keyword in the search box.
Use the category tags to filter by service type (Web, Email, Database, etc.).
Review the protocol (TCP/UDP), category, and security risk for each port.
Click any port number to copy it to your clipboard.
Red badges indicate high-risk ports; green badges indicate TLS-secured ports.

❓ FAQ

What are well-known ports?

Well-known ports range from 0 to 1023 and are assigned by IANA (Internet Assigned Numbers Authority) to specific services and protocols. Examples include port 80 for HTTP, 443 for HTTPS, and 22 for SSH.

What is the difference between TCP and UDP?

TCP (Transmission Control Protocol) is connection-oriented, ensuring reliable data delivery with error checking. UDP (User Datagram Protocol) is connectionless and faster but does not guarantee delivery. Some services use both protocols on the same port number.

What does "high risk" mean?

High-risk ports are commonly targeted by attackers due to known vulnerabilities, weak authentication, or the sensitive nature of the data they handle. Examples include Telnet (23), FTP (21), and RDP (3389). These ports should be firewalled or secured with encryption where possible.

Why are some ports marked as TLS?

TLS (Transport Layer Security) ports use encryption to protect data in transit. For example, HTTPS (443), IMAPS (993), and SMTPS (465) are TLS-secured versions of their plaintext counterparts. Using TLS-encrypted ports is strongly recommended.

How many ports are there in total?

There are 65,535 TCP ports and 65,535 UDP ports. Ports 0–1023 are well-known ports, 1024–49151 are registered ports, and 49152–65535 are dynamic/private ports. This tool covers the most commonly used ports.

🔗 Related Tools

📚 Further Reading

Want to go deeper? These tutorials pair well with this tool.

📄10 Online Tools Every Developer Should Bookmark 📄JSON Formatting & Validation: 5 Tips Every Developer Needs 📄Regular Expressions for Beginners: Patterns, Groups & Online Testing in 30 Minutes

Browse all tutorials →