Ping
Reachability + latency probe — DNS resolve, 3× TCP connect, and an HTTP HEAD. Catches what most users actually mean by “is this site up?”
What is ping?
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The original network probe: is anybody home?
The classic ping uses ICMP echo, but a lot of hosts (Cloudflare, AWS Shield, hardened firewalls) drop ICMP — so an ICMP non-response often doesn't mean the host is actually down. This tool answers the question users usually mean instead: is this thing serving traffic, and how fast?
It resolves the hostname, opens 3 TCP connections to port 443 (falling back to 80), and runs an HTTP HEAD request to report the response code. Private and reserved IP ranges are refused so the tool can't be turned into an internal-network mapper.