AAAA Record Lookup - Free IPv6 DNS Checker

An AAAA record lookup shows the IPv6 addresses a domain or hostname points to. AAAA ("quad-A") records do for IPv6 what A records do for IPv4. The name comes from the address size: an IPv6 address is 128 bits, four times the 32 bits of IPv4.

How to check AAAA records

1. Enter a domain or hostname, such as example.com.
2. Choose a DNS server and click Search.

From a terminal: dig example.com AAAA or nslookup -type=AAAA example.com.

Understanding your results

• Value is the IPv6 address, written as hex groups with runs of zeros shortened to ::.
• No AAAA record means the name is reachable over IPv4 only. That still works for nearly everyone, because IPv6-only users reach IPv4 sites through their provider's translation.
• Both A and AAAA records make the site "dual-stack". Browsers try IPv6 first and fall back to IPv4 quickly if it fails.

Common AAAA record problems

• AAAA left pointing at the old server. The most common migration mistake: the A record is updated, the AAAA isn't, and visitors with IPv6 still reach the old host. Update or remove both together.
• AAAA set but the server doesn't listen on IPv6. Browsers recover by falling back to IPv4, but other software (mail servers, APIs, monitoring) may report the site as down.
• Firewall rules written only for IPv4. Opening a port for IPv4 doesn't open it for IPv6; check both.

Frequently asked questions

Do I need an AAAA record?

Why is it called AAAA?

How can I tell if my own connection uses IPv6?

How do I calculate an IPv6 subnet?