DNS tools

Free online DNS lookup. Query A, AAAA, MX, TXT, NS, CNAME, PTR and SRV records for any domain through a public resolver, with a clear pass/fail verdict and a fix tip.

Free DNSSEC validation. Check if a domain is DNSSEC-signed and its chain of trust validates (DNSKEY, DS, algorithms), and catch broken/bogus DNSSEC that makes a domain unresolvable.

Free nameserver and DNS zone health check: are your nameservers reachable, IPv6-capable, EDNS/TCP-ready and consistent, are SOA timers sane, and do your records have clean TTLs (no too-low / mixed TTLs, MX-to-CNAME, or NS/MX pointing at an IP)?

Free DNS delegation check. Compares the NS set your registry hands out against your zone's own NS records, verifies glue for in-bailiwick nameservers, detects lame delegations, and confirms the DS↔DNSKEY chain — the registry-side problems other checks miss.

Free DNS propagation checker. Query a domain's A, AAAA and NS records from multiple public resolvers (Google, Cloudflare, Quad9, OpenDNS) at once to see whether a DNS change has propagated, or to spot GeoDNS / split-horizon and inconsistent answers across resolvers.

Free open DNS resolver test. Check whether a nameserver on UDP/53 recursively answers for domains it isn't authoritative for, amplifies ANY queries for DDoS reflection, allows AXFR zone transfers, or leaks its version.bind — with fixes.