DNS Lookup

What each DNS record type does

DNS is the internet's phone book, and each record type answers a different question. A records map a hostname to an IPv4 address and AAAA to IPv6 — these are what your browser resolves before connecting. CNAME aliases one name to another (common for www and for pointing custom domains at a hosting platform). MX records tell the world which servers accept mail for the domain, with lower priority numbers tried first. TXT records hold arbitrary text and have become the workhorse of domain verification and email security — SPF policies, DKIM keys, DMARC rules and "prove you own this domain" tokens all live there. NS records name the authoritative nameservers for the zone, and the SOA record carries the zone's administrative metadata: the primary nameserver, the hostmaster contact and the serial number that secondaries use to detect changes.

Debugging DNS problems with this tool

Most "my site is down" and "my email isn't arriving" mysteries resolve to DNS. If a domain won't load, check its A/AAAA records — a missing record or one pointing at an old server IP is the usual culprit after a migration. If email bounces, check MX (does it point at your provider?) and TXT (is the SPF record present and syntactically valid — and is there exactly one?). If a custom domain won't verify with a SaaS platform, check that the CNAME they asked for actually resolves. And when you've just changed a record but still see the old value, remember TTLs: resolvers cache each record for the TTL shown, so a record with a 3600-second TTL can legitimately serve stale data for an hour after you change it. The "Query all" button gives you the full picture of a domain in one shot.

FAQ

Why do results here differ from what I see on my machine?

Lookups run from our server's resolver, not your device — so you see public DNS without your laptop's cache, your router's cache or your corporate network's overrides. If this tool shows the new value but your browser still hits the old server, your local cache hasn't expired yet (try resolvectl flush-caches on Linux or restarting your browser).

Why does my apex domain have no CNAME?

The DNS spec forbids a CNAME at a zone apex (like example.com), because it would conflict with the SOA and NS records that must exist there. That's why hosting providers offer ALIAS/ANAME records or plain A records for apex domains, and reserve CNAMEs for subdomains like www.

What does the SOA serial number mean?

It's the zone's version counter — secondary nameservers compare serials to decide whether to re-fetch the zone. Many operators encode the date of the last change as YYYYMMDDnn, so a serial of 2026072101 reads as "first change on 21 July 2026". If it never changes after you edit records, your provider's primary isn't propagating.