Glossary / AAAA record

AAAA record (DNS IPv6 record)

An AAAA record (quad-A) maps a domain to a server's IPv6 address, the modern IP format that looks like 2606:4700:4700::1111. It does the same job as an A record but for IPv6 networks. You need it so the site opens for visitors who connect over IPv6.

The world has almost run out of IPv4 addresses, so the internet is slowly moving to IPv6 - longer addresses made of hexadecimal groups separated by colons. An AAAA record stores exactly that address and hands it to browsers that support IPv6.

An AAAA record is not mandatory: without one, a device simply falls back to the A record and IPv4. But if your server has IPv6, adding AAAA is worth it, since many mobile and home ISPs now prefer IPv6.

The key is that A and AAAA point to the same site. If AAAA points at an old or broken IPv6 address, some visitors get an error even though the site loads fine over IPv4.

Example

example.com.  3600  IN  AAAA  2606:4700:4700::1111

Common mistakes

• Thinking AAAA is outdated or redundant; it is the record for modern IPv6, not a typo.
• Adding AAAA when the server has no working IPv6 address, which sends IPv6 visitors to an unreachable host.
• Forgetting to update AAAA after a migration, so IPv6 still points to the old server while IPv4 is already new.
• Miscounting the "A"s: A is IPv4, AAAA is IPv6, the name hints at the four-times-longer address.

Related terms

• A record A record (DNS address record)
• CNAME record CNAME record (DNS alias)
• MX record MX record (mail exchanger)
• TXT record TXT record (DNS text record)
• NS record NS record (name server record)