DNS Lookup

DNS-over-HTTPS to the resolver you choose above, only when you press Lookup. Cloudflare answers the JSON API; every other resolver and custom endpoints use RFC 8484 wireformat. Resolvers under "Filtered" refuse to resolve known malicious domains, so an empty answer from one of them is not proof the name does not exist. On networks that block DoH providers (e.g. NextDNS "Block Bypass Methods"), use your own resolver's DoH URL as a custom endpoint. A custom endpoint must allow requests from web pages (CORS); some do not, for example dns.nextdns.io.