Cloudflare 1.1.1.1 is primary. Google Public DNS is used only when the primary request fails.
RDAP.org is primary. IANA bootstrap registries locate the authoritative registry directly when discovery fails.
ipapi is primary; ipwho.is and FreeIPAPI are ordered failure fallbacks. Results remain approximate.
RIPEstat supplies BGP, ASN, RPKI and abuse-contact evidence. These datasets are not replaced with unrelated geolocation guesses.
Globalping supplies live distributed probes. RIPE Atlas is catalogued as an optional future source because it requires credentials and measurement credits.
NetworkCalc supplies the live certificate. crt.sh supplies public subdomain history, while Cert Spotter is an authenticated failure fallback and separately labeled issuance source.
Why there is no random rotation
Changing providers on every request would reduce cache hits, make repeated results inconsistent and can violate provider quotas. DNSTrace.dev caches successful public results, records the source, respects Retry-After and falls back only for operational failure.
Machine-readable inventory
The live catalog, documentation links, access notes and runtime status are available from GET /api/providers.