Port Scanner
Scan common ports on a host to identify open services. Checks top 20 TCP ports.
A port scanner checks whether specific network ports on a host are accepting connections, revealing which services are exposed. This tool probes the 20 most common TCP ports — web, mail, SSH, databases, and more — and reports each as open, closed, or filtered. Use it for a quick exposure check of your own servers; results are indicative rather than a full security audit.
Frequently asked questions
What do open, closed, and filtered mean?
Open means a service responded, closed means the port refused the connection, and filtered means no response came back (often a firewall dropping packets) so the state is unknown.
Which ports does it check?
The 20 most common TCP ports, including 80/443 (web), 22 (SSH), 25 (SMTP), 3306 (MySQL), and 3389 (RDP).
Why are open ports a risk?
Every exposed service is a potential entry point. Closing or firewalling ports you don’t need shrinks your attack surface.
Why might results differ from nmap?
This scanner probes over HTTP from a serverless edge, so non-HTTP services can read as filtered and some outbound ports are blocked. Use a dedicated scanner for authoritative results.
Is it legal to scan a host?
Only scan systems you own or are authorised to test. Unsolicited scanning of third-party hosts may breach acceptable-use policies or local law.