IPv6 Compatibility Checker
Test whether a domain is genuinely IPv6-ready by checking its website, name servers and mail servers for working IPv6 addresses - run from our EU servers.
About IPv6 Compatibility Checker
The IPv6 Compatibility Checker inspects a domain across the three services that determine real-world IPv6 reachability: its website, its authoritative DNS and its mail. Enter a domain and the tool queries live DNS records from our servers and reports a pass or fail for each layer, so you can see not just whether AAAA records exist but whether every part of the domain's infrastructure can actually be reached over IPv6.
For the website it looks up AAAA records on both the apex domain (example.eu) and the www hostname (www.example.eu), and passes if either publishes an IPv6 address. An AAAA record is the IPv6 equivalent of an A record: it maps a hostname to a 128-bit IPv6 address, and its presence is what lets an IPv6-only client load the site directly.
For DNS it resolves each of the domain's NS records and checks whether those name servers themselves have AAAA records, because a domain is only fully IPv6-reachable if a client on an IPv6-only network can resolve it in the first place. For mail it resolves each MX host and checks for AAAA records, so you can confirm mail can be delivered over IPv6; if the domain publishes no MX records, the mail check is reported as not applicable rather than as a failure.
Full IPv6 support requires all three layers, and it is common for a site to serve its web page over IPv6 while its DNS or mail still runs IPv4-only. The checks run from our EU servers against public DNS, so the result reflects the domain's published records rather than anything about your own connection.
How to use it
- 1Enter the domain you want to test (for example example.eu) - no https:// and no path, just the domain.
- 2Select Test IPv6 to run the live checks from our servers.
- 3Review the three results: website AAAA records, IPv6-reachable name servers and IPv6-reachable mail servers.
- 4Note any layer marked with a cross - that service still needs an AAAA record added to be reachable over IPv6.
Common use cases
- -Confirming a site is fully IPv6-ready before an ISP, registrar or compliance programme requires it.
- -Diagnosing why IPv6-only clients can reach a website but not its mail or DNS.
- -Auditing a portfolio of domains for missing AAAA records on web, DNS or MX hosts.
- -Verifying that an IPv6 rollout actually took effect across every layer of a domain's infrastructure.
Frequently asked questions
- What makes a domain IPv6-ready?
- A domain is fully IPv6-ready when its website, its name servers and its mail servers all publish AAAA records and can be reached over IPv6. Publishing an AAAA record on the website alone is not enough if DNS or mail still runs IPv4-only.
- What is an AAAA record?
- An AAAA record is a DNS record that maps a hostname to a 128-bit IPv6 address, the IPv6 counterpart of the 32-bit A record. It is what allows an IPv6-capable client to connect to a host directly over IPv6.
- Why does my website work over IPv6 but the test still fails?
- The checker tests three layers, not one. A site can serve its web page over IPv6 while its authoritative name servers or MX mail hosts have no AAAA records - meaning IPv6-only clients cannot resolve or email the domain - and any missing layer is flagged.
- Does this test my connection or the domain?
- It tests the domain. The checks run from our EU servers against the domain's public DNS records, so the result reflects what the domain publishes, independently of whether your own network has IPv6.
- What happens if the domain has no mail servers?
- If the domain publishes no MX records, the mail check is reported as not applicable rather than as a failure, since there is no mail service to reach over IPv6 in the first place.