DNS Checker
Look up every common DNS record for a domain or subdomain, then see whether major public resolvers such as Google, Cloudflare and Quad9 all return the same address.
Reading the results
A missing MX record means the domain cannot receive email. A TXT record starting with v=spf1 lists who may send mail for it. An empty CAA set means any certificate authority may issue certificates, which is the default but not the safest choice.
A CNAME pointing at a cloud service that no longer exists is the classic setup for a subdomain takeover.
Frequently asked questions
Which DNS records does this check?
A and AAAA (addresses), CNAME (aliases), MX (mail servers), NS (authoritative name servers), TXT (SPF, DKIM, DMARC and verification strings), SOA (zone authority and timers) and CAA (which certificate authorities may issue for the domain).
What is DNS propagation?
After a DNS change, resolvers keep serving the old answer until their cached copy expires. The resolver table asks eight public resolvers for the A record right now, so a row still showing the old address means that operator has not picked up the change yet.
Why do different resolvers show different IPs?
Either one resolver still has the old answer cached, or the domain uses geographic routing or a CDN that answers different networks with different servers. These resolvers are anycast, so each one answers from its node nearest our server in Europe. If the difference is stable over time, it is routing rather than propagation.
Which resolvers are compared?
Cloudflare, Google, Quad9, OpenDNS, AdGuard, Yandex, Control D and DNS.SB, plus the C99 DNS service. The full record set above comes from Cloudflare and Google. Results are cached for five minutes.
Free to use within a daily limit per visitor. Use it on systems you own or are allowed to test, see the acceptable use policy.