Free online DNS server scanner and testing tool. 135+ DNS health checks across 18 categories: delegation consistency, DNSSEC chain-of-trust, EDNS compliance, DNS over HTTPS/TLS/QUIC, DDR encrypted-resolver discovery (RFC 9462), ECH (Encrypted Client Hello) config validation in HTTPS records (RFC 9460), response consistency across repeated queries, security vulnerabilities, SOA serial consistency, and more. Graded 0–100 with an A–F letter grade. Export JSON or CSV.