Web / DNS Tools

Port Scanner

Scan a preset group of common TCP ports on any host and see which are open.

Server-assisted public lookup

Check a single port instead

Ports in this preset

Scanning ports…

Host scanned

Open
Closed

Total ports

Scan Results
Port Status Service Response

What is the Port Scanner?

The Port Scanner scans a range of common TCP ports on a target host and reports which are open, closed, or filtered. Rather than checking one port at a time, it gives you a rapid overview of all services exposed on a server - invaluable for network security audits, server hardening, and infrastructure troubleshooting.

Open ports on your server represent potential attack surfaces. Best practice is to close or firewall any port not actively needed. Most public-facing servers should only have ports 80 (HTTP), 443 (HTTPS), and optionally 22 (SSH on a non-standard port) open to the internet.

How to use the Port Scanner

Enter a hostname or IP address and select which set of ports to scan - Top 20 common ports for a quick check, Top 100 for a thorough audit, or enter a custom range. Click Scan and results appear as each port is tested. Open ports are highlighted in green, filtered ports in amber, and closed ports shown as grey.

Frequently asked questions

A port scanner checks several common TCP ports at once to discover which services are exposed on a host - useful for inventorying your own servers.
Scanning servers without permission may be illegal in your jurisdiction. Only scan hosts you own or have written permission to scan.
It checks well-known ports for HTTP, HTTPS, SSH, FTP, SMTP, POP3, IMAP, DNS, MySQL, PostgreSQL, Redis and more.
Each port has a short timeout to detect closed services. Total time depends on how many ports time out vs. respond quickly.