WhoDNS

Network Tools

Ping, A Record lookup, HTTP test and Port status

Ping Test Check host reachability A Record Query A/AAAA records PTR Lookup Reverse DNS & IP owner HTTP Test Check HTTP status and headers Port Check Check TCP/UDP port status
Enter a host or IP address.
Single port (1-65535)
Comma-separated — max 20 ports

Frequently Asked Questions

What is a port check used for?
It determines whether a port on a host is open or closed; useful for troubleshooting services like web (80/443), email (25/587) or databases.
What is the difference between TCP and UDP here?
TCP is connection-oriented so open/closed is determined clearly; UDP is connectionless, so it is sometimes impossible to say definitively whether it is open or simply not replying.