DNS lookup

What it does: looks up the records behind a domain name — the "phone book" of the internet. DNS is what turns a name like example.com into the address and mail/verification info computers actually use.

Which resolver: by default the DNS server(s) set on this machine's network adapters, so nothing new leaves your network path; only if you tick "Use Cloudflare DoH (public)" does Cloudflare see the name you looked up. Internal names those servers know (intranet hosts, AD domains) resolve. It asks those servers directly — it is not the operating system's resolver: the hosts file, DNS search suffixes and VPN split-DNS (NRPT) rules are not applied, so type full names, and a name that only resolves over a split-tunnel VPN may differ from what other programs get. Tick "Use Cloudflare DoH (public)" to ask Cloudflare over DNS-over-HTTPS instead — handy to compare against a public answer, or on a network whose DNS is broken — but then Cloudflare sees the name you looked up. The status line always says which resolver answered, and each row shows the name it belongs to, so a CNAME chain reads step by step.

What you need: a domain name (e.g. example.com) and one record type from the picker: A, AAAA, MX, TXT, NS, CNAME, SOA, PTR, SRV or CAA.

Safe to run: yes — a read-only lookup.

What to expect / reading results: each record type answers a different question — A = the IPv4 address, AAAA = the IPv6 address, MX = which mail server handles the domain, TXT = things like SPF/domain-verification. "NXDOMAIN" means the name doesn't exist (a typo, or it was never registered); an empty result for one type just means the domain has no record of that type.