Reverse DNS (PTR) Lookup
Forward DNS maps a domain to an IP; reverse DNS (PTR) maps an IP back to a hostname. This tool builds the in-addr.arpa (IPv4) or ip6.arpa (IPv6) name automatically and looks up its PTR live.
PTR matters for telling datacenter from residential, tracing mail servers and investigating abuse — a datacenter IP's PTR often reveals the cloud (e.g. amazonaws / googleusercontent). Queries go via Cloudflare DoH, never through our server.
Reverse DNS (PTR) resolves an IP back to a hostname, via Cloudflare 1.1.1.1 DoH — no server relay. Mail servers, tracing, and datacenter-vs-residential checks rely on it; a datacenter IP's PTR often reveals which cloud it is.
Check this IP's purity — datacenter or residential →