AAAA What is an AAAA Record?
An AAAA record maps a hostname to an IPv6 address. Learn why it's called quad-A, how it coexists with A records, and why IPv6 adoption matters.
What is an AAAA record?
An AAAA record maps a hostname to an IPv6 address. It is the IPv6 equivalent of the A record. The name "quad-A" comes from the fact that an IPv6 address is 128 bits — four times the 32 bits of an IPv4 address.
Most production servers offer both A (IPv4) and AAAA (IPv6) records so that clients can connect using whichever protocol they support. Modern browsers use an algorithm called Happy Eyeballs to try both in parallel and use whichever connects first.
Anatomy of an AAAA record
example.com. 3600 IN AAAA 2606:2800:220:1:248:1893:25c8:1946| Field | Value | Description |
|---|---|---|
| Name | example.com. | The hostname being mapped. |
| TTL | 3600 | Time-to-live in seconds. |
| Class | IN | Internet class. |
| Type | AAAA | Record type: IPv6 address. |
| Address | 2606:2800:220:1:248:1893:25c8:1946 | 128-bit IPv6 address in colon-separated hexadecimal groups. |
IPv6 address notation
IPv6 addresses are 128 bits written as eight groups of four hexadecimal digits, separated by colons. Two consecutive colons (::) represent one or more groups of all zeros:
Full: 2001:0db8:0000:0000:0000:0000:0000:0001
Compressed: 2001:db8::1When to add AAAA records
- When your server has an IPv6 address assigned (most modern VPS and cloud providers do)
- When you want to support IPv6-only networks (increasingly common on mobile)
- When using a CDN — most CDNs handle AAAA records automatically
Adding a AAAA record alongside your A record is generally safe. If a client doesn't support IPv6, it will use the A record instead.
Frequently asked questions
Why is it called AAAA and not A6?
The name comes from the address size — IPv6 addresses are 128 bits, four times the 32-bit IPv4 address. AAAA = four A's = four times the address space. (An A6 record type was briefly proposed but deprecated.)
Do I need both A and AAAA records?
Not strictly required, but recommended. Having both ensures your site is reachable over IPv4 and IPv6. Clients automatically choose based on their connectivity.
Can I have a AAAA record without an A record?
Yes. An IPv6-only server would only have a AAAA record. However, some networks and clients don't support IPv6, so they won't be able to reach it.