Glossary / dns-over-https

DNS-over-HTTPS (DoH)

DNS resolution wrapped in HTTPS, used as a fast secondary availability signal.

DoH encrypts DNS queries inside ordinary HTTPS traffic, preventing on-path observation and tampering. Public resolvers like Cloudflare (1.1.1.1) and Google expose JSON APIs for it.

For availability checking, an NXDOMAIN answer (RCODE 3) to an NS query says no delegation exists for the name — usually meaning unregistered, though a registered-but-undelegated domain can produce the same answer. That's why DoH-based results deserve a lower confidence score than registry RDAP answers.

DomainFind.ai uses Cloudflare's DoH endpoint as its fallback verification path and reports such results with method 'dns' and confidence around 0.75, so consumers know to re-verify before high-stakes decisions.

Related terms

• RDAP (Registration Data Access Protocol) — The modern, HTTPS-based successor to WHOIS that returns structured JSON registration data.
• Domain Availability — Whether a domain can be registered right now at standard pricing.

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