When it comes to free online port scanner tools, several options stand out for their reliability and features:
Pentest-Tools.com Port Scanner
This tool offers an online Nmap scan with zero setup, allowing you to check open TCP and UDP ports from an external perspective. It’s effective for identifying open ports and assessing network security.
HackerTarget.com Nmap Online Port Scanner
Utilizing Nmap, this online scanner tests open ports and firewalls, providing accurate port status from an external viewpoint. It supports scanning single IP addresses or ranges.
DNS Checker Port Scanner
This port checker identifies open and closed ports using traditional TCP and UDP scanning techniques, ensuring accurate results.
Advanced Port Scanner
A free network scanner that quickly finds open ports on network computers and retrieves versions of programs running on the detected ports. It features a user-friendly interface and rich functionality.