What is a DNS lookup?
A DNS lookup asks the Domain Name System what is published for a name. DNS stores different kinds of records for each domain: addresses for its website, the servers that accept its email, text records used for verification and email security, and the nameservers that hold all of it.
What each record type means
| Type | What it holds | Typical use |
|---|---|---|
| A | An IPv4 address | Points the name at a web server |
| AAAA | An IPv6 address | The same, for IPv6 networks |
| CNAME | An alias to another name | www pointing at a hosting provider |
| MX | Mail servers and their priority | Where email for the domain is delivered |
| NS | The authoritative nameservers | Which DNS provider answers for the domain |
| TXT | Free-form text | SPF, domain verification, DKIM keys |
| CAA | Certificate authorities allowed to issue | Limits who can issue TLS certificates |
| SOA | Zone metadata and serial number | Shows the primary nameserver and when the zone last changed |
How to read the results
Each record type is queried separately and shown as its own group. A group marked as empty means the name exists but has no record of that type, which is normal — most domains have no CNAME at the root, and many have no AAAA.
- No records at all usually means the name does not exist: a typo, or a domain that has not been registered or delegated.
- No A or AAAA means the name has no address, so nothing can connect to it as a website.
- One nameserver is a single point of failure. The DNS standard (RFC 1034) expects at least two.
- A CNAME alongside MX or NS is invalid: a CNAME cannot share a name with other records.
- No AAAA is only a note. The site works, but not over IPv6-only connections.
Queries go to the public resolver 1.1.1.1, so you see what the wider internet sees, including cached answers. That is the right view for checking whether a change has taken effect for real visitors.
Why a DNS change is not visible yet
DNS does not push changes out. Every record carries a TTL — a number of seconds resolvers may keep a cached copy. After you edit a record, resolvers that already hold the old answer keep serving it until their copy expires. People call this propagation, but it is really just caches timing out.
To make a planned change take effect quickly:
- Lower the record's TTL to 300 seconds a day or two before the change.
- Make the change, then confirm it here.
- Raise the TTL back to an hour or more once everything works.
Common fixes
Website does not load on the bare domain. The root needs its own A/AAAA record. A www record does not cover it:
example.com. A 203.0.113.10
www.example.com. CNAME example.com.CNAME at the root is rejected. The DNS standard does not allow a CNAME at the zone apex, because the apex must also hold NS and SOA records. Use your DNS host's ALIAS, ANAME or CNAME-flattening feature instead.
Email stopped after moving DNS providers. MX and TXT records are easy to leave behind in a migration. Compare this output with the old zone, then check them directly with the MX lookup and SPF checker.