What Is an AAAA Record
Learn what an AAAA record is, how it maps hostnames to IPv6 addresses, and when AAAA records matter for websites and DNS.
Introduction
AAAA records are the IPv6 equivalent of A records. They tell DNS which IPv6 address should receive traffic for a hostname.
Many sites work fine with only A records, but if AAAA exists it must be correct — otherwise IPv6-enabled networks may prefer the wrong destination.
Quick answer
An AAAA record maps a hostname to an IPv6 address, similar to how an A record maps to IPv4. If AAAA points to the wrong server or your host does not support IPv6, some visitors may fail to reach your site.
What it means
AAAA (pronounced “quad A”) connects a domain name to a 128-bit IPv6 address. When both A and AAAA exist, clients may try IPv6 first depending on network settings.
- Used when your server or CDN supports IPv6
- Works alongside A records for dual-stack hosting
- SSL validation and website access can fail if AAAA is wrong
- Remove AAAA if your server does not listen on IPv6
Where you see this:
- Dual-stack web hosting with IPv4 and IPv6
- CDN or cloud providers that publish IPv6 endpoints
- Modern networks where clients prefer IPv6 when available
example.com. 300 IN AAAA 2001:db8::10Why this matters
An outdated AAAA record can send IPv6 users to the wrong server even when the A record is correct. That causes confusing migration problems where “the site works for some people but not others.”
How to check it
- Run DNS Lookup and check for AAAA answers.
- Compare the IPv6 address with your hosting or CDN documentation.
- Test from an IPv6-capable network if possible.
- Run dig +short example.com AAAA from the command line.
- If IPv6 is unused, confirm whether an old AAAA record should be removed.
Look up AAAA records
Use DNS Lookup to see whether a domain publishes IPv6 addresses and where they point.
Common mistakes
AAAA still points to old server
HighIPv6 traffic reaches a previous host after migration.
Next step: Update or delete the AAAA record at authoritative DNS.
IPv6 not configured on web server
MediumDNS publishes AAAA but the server does not accept IPv6 connections.
Next step: Enable IPv6 on the server or remove the AAAA record.
Only A record updated during migration
HighIPv4 users see the new site; IPv6 users may still see the old one.
Next step: Update A and AAAA together or remove unused AAAA.
CDN IPv6 mismatch
MediumAAAA points to CDN while origin IPv6 differs or is disabled.
Next step: Align AAAA with your CDN or hosting provider instructions.
Example
example.com. 300 IN AAAA 2001:db8:85a3::8a2e:370:7334Frequently asked questions
Do I need an AAAA record?
Only if your hosting or CDN supports IPv6 and you want IPv6 visitors to reach your site. Many domains use A records only.
What is the difference between A and AAAA?
A records use IPv4 addresses like 192.0.2.10. AAAA records use IPv6 addresses like 2001:db8::10.
Can AAAA break SSL or validation?
Yes. If AAAA points to the wrong host, certificate issuance or HTTPS access over IPv6 can fail.
Should I delete AAAA if I do not use IPv6?
Often yes, if the record points to an old or non-responsive server. Removing stale AAAA prevents split behavior between IPv4 and IPv6 clients.
Related tools
Use these free tools to verify your configuration after applying changes.
Related guides
Browse all Glossary guides →Need help applying this fix?
Send us your domain, report link or issue details. CheckDomainHealth will review the request and route it to the right technical team if hands-on support is needed.
Was this guide helpful?
Your feedback helps us improve our guides for everyone.
Thanks for your feedback!