What IPv6 readiness means and why you should care
IPv6 is the new version of internet addresses. The old one, IPv4, only has about 4 billion possible addresses and we already ran out. Every new device at home, every phone on a mobile network, every server in a modern cloud data center now gets an IPv6 address. Your domain should have one too.
This tool takes your domain and runs five tests: asks DNS for an AAAA record (the IPv6 address) of the apex, of www, of your mail servers (MX), of your nameservers (NS), and finally opens an actual TLS connection to your server over IPv6 to check that it answers. Each test contributes between 0 and 40 points. Everything adds up to a single 0 to 100 score and an A to F letter grade.
Why care in 2026? Because mobile carriers in many countries hand out IPv6-only addresses to new customers (T-Mobile US, Reliance Jio, parts of Orange and Vodafone). Because AWS and Google Cloud now charge extra for every IPv4 address. Because websites without IPv6 are simply slower for IPv6-only users (they must pass through a NAT64 translator). And because you want your site reachable for everybody, not just for half of the internet.
How to use it
- Type a domain: just the bare name, no `https://`, no path. A subdomain works too (`blog.brand.com`), but the most meaningful score is the apex people type into the browser.
- Click "Check". The test takes 2 to 8 seconds: we query DNS for five things and open one real TLS connection over IPv6.
- Read the big number at the top - that is the sum of points from the five components. A is 85 or higher, F is under 30. Many domains in 2026 still sit in the C-D range.
- Below the score you get 5 cards, one per test. Each says passed (green), failed (red) or partial (amber), how many points it gave, and what exactly happened.
- Click "Details" to expand the raw evidence: which IPv6 addresses were found, which MX targets have AAAA, which TLS protocol came back on the handshake. Copy-paste straight to your sysadmin.
- If you get 0 or a very low score, this is not a bug. It means your hosting / DNS / mail are still IPv4-only. Talk to your hosting provider about dual-stack.
- Compare different domains: `cloudflare.com` (always A), `google.com` (always A), `example.com` (varies), your own. That comparison alone shows the scale of the gap.
When this is useful
Seven concrete situations where this tool gives you a usable answer instead of a vague feeling:
- Corporate domain audit before a migration. A client asks "will our new site work for an IPv6-only carrier?". You type the domain, you get an A = yes, F = no. The letter grade ends the conversation without you having to explain what AAAA is.
- Holding your hosting provider accountable. They advertise "full IPv6 support" and you measure an F. You paste the report and demand they enable AAAA on the apex and www. Direct evidence, no debate.
- Competitive check. Type a competitor's domain into the field. You see they are A. You bring that back to your team: "they already have it, we do not". Much easier sell internally.
- Mail migration to a new host. You are moving mailboxes. The test shows whether MX over IPv6 works - that matters because big senders (Gmail, Office 365) are starting to send from IPv6, and dual-stack MX cuts delivery friction.
- Pre-launch DNS audit. Before you flip the domain live, you check that NS records have AAAA. Without that, an IPv6-only resolver cannot even resolve your DNS before falling back.
- Pressure on cheap registrars. Some budget registrars hand out NS hosts without AAAA - this test surfaces that (the "NS IPv6" component returns 0). A solid argument to switch registrar or move DNS to Cloudflare / Route 53 / Bunny DNS.
- Post-change verification. You just flipped on AAAA in the Cloudflare dashboard. Five minutes later you type your domain here, you see the score jump from 0 to 40+. Concrete proof the change took effect.
Related: DNS Lookup (see every DNS record, not just AAAA), Email DNS Checker (audit SPF/DKIM/DMARC for mail), SSL Certificate Inspector (inspect your certificate chain over TLS).