Is your site reachable for crawlers connecting over the modern IPv6 internet?
Major crawlers run on dual-stack networks, and IPv6-only AI inference clusters are growing fast.
What this signal tests
We check whether your site is reachable over IPv6 - the modern internet addressing system that has gradually been replacing the older IPv4. We confirm your DNS publishes AAAA records (the IPv6 equivalent of the classic A record), and we connect to your site over IPv6 to verify it returns the same content over the modern protocol as it does over the older one.
Why it matters for your visibility in AI
Major crawlers from Google, OpenAI, Anthropic, and the cloud platforms hosting AI infrastructure all operate dual-stack networks, where outbound connections can use either IPv4 or IPv6 depending on availability. As IPv6 deployment continues, more AI inference and crawling traffic originates from IPv6-only networks. A site that is only reachable on IPv4 will be visited less reliably and risks being treated as a flaky source. This is a low-weight issue for most small businesses today, but the cost of fixing it is also low - usually a single CDN setting or DNS record. Sites that proactively enable IPv6 also gain a measurable speed advantage in some regions, especially Asia, where IPv6 connectivity is often better than IPv4. It is a small, future-proofing improvement that costs almost nothing.
Pass criteria at a glance
| Criterion | Passes when |
|---|---|
| AAAA present AND IPv6 fetch returns equivalent body. |
How we test it
We query DNS for AAAA records on both your apex domain (example.com) and the www variant. If present, we open a TLS connection to that IPv6 address on port 443, fetch the homepage, and compare the response body against what we received earlier over IPv4. The two should be effectively identical; any major difference is flagged because it usually indicates a misconfiguration where IPv4 and IPv6 land on different hosts.
Show technical detection method
DNS AAAA on apex and www; TLS connect to [v6]:443; confirm 200 on `/`; compare to IPv4 body hash.
If your site fails: how to fix it
- Check whether your DNS provider supports AAAA records - every major provider does today. If not, switch to one that does (Cloudflare, Route 53, Google Cloud DNS, etc.).
- If your CDN already supports IPv6 (Cloudflare, Fastly, Akamai, AWS CloudFront, all do), enabling it is often a single toggle in the dashboard. The CDN takes care of the AAAA record and the IPv6 termination.
- If you host your origin server yourself, ask your hosting provider to provision an IPv6 address for it. Most modern data centres include IPv6 by default.
- Once IPv6 is enabled, fetch your site over IPv6 (curl -6 or a website checker like internet.nl) and confirm you receive the same content as over IPv4.
- Re-run the AI Ready Test to confirm AAAA records are now published and the IPv6 endpoint returns matching content.
Quick facts
| Maturity | ESTABLISHED |
|---|---|
| Weight | low |
| Category | Crawlability |
Primary sources
Related signals
No related signals listed.
Frequently asked questions
Is this really a problem for AI visibility today?
Today it is a small advantage, not a blocker - which is why we weight it low. But the direction of travel is clear: IPv6-only networks are expanding, particularly in mobile and cloud infrastructure that hosts AI inference. Enabling IPv6 now costs almost nothing and protects against future degradation.
Will enabling IPv6 break my IPv4 traffic?
No. Enabling IPv6 means your site is reachable on both protocols simultaneously. Existing IPv4 users and crawlers continue to work exactly as before; IPv6-capable clients gain the ability to connect over the new protocol when they prefer it.
How do I test IPv6 reachability myself?
Free tools like internet.nl, ipv6-test.com, or simply running curl -6 https://yourdomain.com from a command line will confirm IPv6 reachability. Browser extensions can also show you which protocol your traffic is using.
Do AI crawlers really prefer IPv6?
Not prefer, but they increasingly originate from networks where IPv6 is the default outbound protocol. If you are only on IPv4, those crawlers reach you via NAT64 or other translation, which is slower and slightly less reliable. Native IPv6 is the smoothest path.
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