DNS record types reference
A, AAAA, CNAME, MX, TXT, NS, SOA, CAA, SRV, DS, DNSKEY and HTTPS records: what each one does.
Updated 19 September 2026 · 1 min read
| Type | Purpose | Notes |
|---|---|---|
| A | IPv4 address of a name | Web servers, mail servers |
| AAAA | IPv6 address | Publish both where you can |
| CNAME | Alias to another name | Cannot coexist with other records at the same name; never at the apex |
| MX | Mail exchangers, with priority | Lower number is tried first; targets must be hostnames with A/AAAA |
| TXT | Free text | SPF, DMARC, DKIM keys, site verification tokens |
| NS | Nameservers for a zone | Must match the delegation at the parent |
| SOA | Zone metadata | Primary server, contact mailbox, serial, refresh/retry/expire timers |
| CAA | Which certificate authorities may issue | issue, issuewild, iodef tags |
| SRV | Service location | _service._proto.name, priority, weight, port, target |
| PTR | Reverse mapping from address to name | Set by the address owner; checked by mail receivers |
| DS / DNSKEY / RRSIG | DNSSEC | DS at the parent links to the KSK; RRSIG signs each record set |
| TLSA | DANE certificate binding | Mostly used for SMTP |
| HTTPS / SVCB | Service binding for web | Advertises HTTP/3, ECH and address hints |
Reading TTLs
Every record carries a TTL in seconds. Low TTLs (60 to 300) let you move quickly but cost more queries; long TTLs (3600 and up) are fine for stable records. Lower the TTL a day before a planned change, then raise it again.
Wildcards and subdomains
A *.example.co.uk record answers for any name that does not have its own records. Wildcards do not apply to names that exist with other types, which surprises people setting up mail on a subdomain.
Where whois.me.uk looks
The DNS facet queries each of these types for the apex plus A for www, then asks every authoritative nameserver for SOA and NS to check agreement.
Check your own domain