DNS Lookup — check A, AAAA, NS and MX records
Look up the DNS records of any domain: IPv4 (A), IPv6 (AAAA), nameservers (NS) and mail servers (MX). Resolved against authoritative resolvers and cached for one hour.
How to read the result
- A records (IPv4)
- The addresses the name resolves to. More than one usually means load balancing or a CDN answering on the site's behalf, not several separate servers you control.
- AAAA records (IPv6)
- The IPv6 equivalent. Most sites still have none, and that is not a fault — it means visitors on IPv6-only networks reach you through their provider's translation instead of directly.
- NS records
- The nameservers authoritative for the zone: whoever answers DNS questions about the domain. This is frequently a different company from the one hosting the site, and it is the pair you change to move DNS control.
- MX records
- Where mail for the domain is delivered, each with a priority number. Lower wins; the higher ones are fallbacks. A domain with no MX accepts no mail.
Where this tool is wrong
Every check here reads one signal, and each has a blind spot worth knowing before you act on the answer.
- Answers come from our resolver and are cached for an hour, so a record you changed minutes ago may not appear here yet.
- Some networks run split-horizon DNS and deliberately answer differently depending on who is asking. What you see here is what a public resolver sees, which is what most of your visitors get — but not necessarily what you see from inside the office.
- Many DNS providers flatten a CNAME at the apex into A records before serving it. When that happens the target's addresses appear here and the CNAME itself is invisible.
Common questions
Why does the A record show a Cloudflare address instead of my server?
Because DNS is answering with the CDN's edge, which is the point of putting one in front. The origin address is deliberately not published. A reverse-IP or hosting lookup on that address describes the CDN, not your host.
My domain has no AAAA record. Is that a problem?
Not for reachability — every IPv6-only network can still reach IPv4 sites through its provider. Adding IPv6 is worth doing, but its absence breaks nothing today.
How long after changing a record will it show up here?
Up to an hour, because results are cached. Beyond that it depends on the TTL you set on the record itself: resolvers around the world keep serving the old value until it expires.
Why do two DNS checkers give different answers?
Usually because one of them asked a different resolver, or asked before a change had propagated. Authoritative answers come from the nameservers; everything in between is a cache with its own expiry.