Yes — crystalwg.dev has IPv6.

Has both IPv4 (A) and IPv6 (AAAA) addresses.

This is a saved measurement from 2026-11-02 13:23 UTC. Check crystalwg.dev live now

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 crystalwg.dev has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3030::6815:5fcb answers · 443✓ 2606:4700:3030::ac43:9461 answers · 443	yes
www over IPv6 www.crystalwg.dev has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3030::6815:5fcb answers · 443✓ 2606:4700:3030::ac43:9461 answers · 443	yes
Mail servers (MX) have IPv6 No MX records, so mail goes to the domain's own address (implicit MX). It has an AAAA record.	yes
Nameservers have IPv6 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. jerome.ns.cloudflare.com ✓serena.ns.cloudflare.com ✓	yes

HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate after 1 redirect: HTTP 200.

https://crystalwg.dev/ via 2606:4700:3030::6815:5fcb → 302https://crystalwg.cloudflareaccess.com/cdn-cgi/access/login/crystalwg.dev?kid=3b31dfc01d91e0813420a42ae6ae754194c0435e8a37d22af2b4267312e35781&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6IjMwNmZiNjI2M2ZjZTY2ODk2NWU3OTI5YzVjNjM0NTA4ZDNlYzllNjE1N2NjOTA2NTBmYTBjZTE4Mzc2NDYzZjcifQ.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.wVp-jhODliXg9pvxDvD0GAD7shQxtoOl1tOMjILdbqPkuoDCf9At3CaJsFZTHsMK8bceVSB-SCHa2FpZJ9cLKHqrug6WzjPNNwXle-07d8m3xjTzl69FAxG1LL0ysN9uS7yhqpUSBvjwUcjY8g_wUd_VFyDUMnF7ha-QwDHZBAjx0J3bNcTwKBcRhbPKaAiLcee0-035pG_3Y_V5OEvOAGwPuhvgEz5NXkdOzJWLfnZexZjZ_L20c324Iuie2D7c9gfiJ2_IVJ0d_a-a4ySH38fSLrSq2bVAfNtwHe-N0WlmJdJz310VyCIbQAaGj8B5cb0X5Q_c1jFraRz0iBqxBg&redirect_url=%2F via 2606:4700:300a::6813:c31d → 200

works

Nothing keeping you from an A

Nothing to fix
Show it off: add the badge to your README.
[![IPv6](https://aaaa.bot/badge/crystalwg.dev.svg)](https://aaaa.bot/crystalwg.dev)

Check again

crystalwg.dev Has IPv6

A (IPv4)	104.21.95.203 172.67.148.97
AAAA (IPv6)	2606:4700:3030::6815:5fcb 2606:4700:3030::ac43:9461

www.crystalwg.dev Has IPv6

A (IPv4)	172.67.148.97 104.21.95.203
AAAA (IPv6)	2606:4700:3030::6815:5fcb 2606:4700:3030::ac43:9461

Browsers on dual-stack networks will usually pick IPv6 here (the "Happy Eyeballs" algorithm races both and prefers v6).

Copy the evidence — a citation-ready record of this measurement

IPv6 measurement: crystalwg.dev
Measured 2026-11-02 13:23:24 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    104.21.95.203, 172.67.148.97
AAAA (IPv6): 2606:4700:3030::6815:5fcb, 2606:4700:3030::ac43:9461
www AAAA:    2606:4700:3030::6815:5fcb, 2606:4700:3030::ac43:9461

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: crystalwg.dev has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3030::6815:5fcb: answers (TCP 443)
    2606:4700:3030::ac43:9461: answers (TCP 443)
- www over IPv6: www.crystalwg.dev has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3030::6815:5fcb: answers (TCP 443)
    2606:4700:3030::ac43:9461: answers (TCP 443)
- Mail servers (MX) have IPv6: No MX records, so mail goes to the domain's own address (implicit MX). It has an AAAA record.
- Nameservers have IPv6: 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.

Reachability = a TCP connection opened on port 443 (or 80).

HTTPS over IPv6 (not graded): Loads over IPv6 with a valid certificate after 1 redirect: HTTP 200.
    https://crystalwg.dev/ via 2606:4700:3030::6815:5fcb -> HTTP 302, certificate: valid
    https://crystalwg.cloudflareaccess.com/cdn-cgi/access/login/crystalwg.dev?kid=3b31dfc01d91e0813420a42ae6ae754194c0435e8a37d22af2b4267312e35781&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6IjMwNmZiNjI2M2ZjZTY2ODk2NWU3OTI5YzVjNjM0NTA4ZDNlYzllNjE1N2NjOTA2NTBmYTBjZTE4Mzc2NDYzZjcifQ.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.wVp-jhODliXg9pvxDvD0GAD7shQxtoOl1tOMjILdbqPkuoDCf9At3CaJsFZTHsMK8bceVSB-SCHa2FpZJ9cLKHqrug6WzjPNNwXle-07d8m3xjTzl69FAxG1LL0ysN9uS7yhqpUSBvjwUcjY8g_wUd_VFyDUMnF7ha-QwDHZBAjx0J3bNcTwKBcRhbPKaAiLcee0-035pG_3Y_V5OEvOAGwPuhvgEz5NXkdOzJWLfnZexZjZ_L20c324Iuie2D7c9gfiJ2_IVJ0d_a-a4ySH38fSLrSq2bVAfNtwHe-N0WlmJdJz310VyCIbQAaGj8B5cb0X5Q_c1jFraRz0iBqxBg&redirect_url=%2F via 2606:4700:300a::6813:c31d -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/rk5kAv1DPU

Permanent link: aaaa.bot/r/rk5kAv1DPU · How we measure

Checked 2026-11-02 13:23:24 UTC. Full DNS report: dns.pizza/domain/crystalwg.dev · JSON: /api/v1/crystalwg.dev