Yes — sphinx.best has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 sphinx.best has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3033::ac43:ba16 answers · 443✓ 2606:4700:3032::6815:5429 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. adaline.ns.cloudflare.com ✓vin.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://sphinx.best/ via 2606:4700:3033::ac43:ba16 → 302https://cool-paper-fbfe.cloudflareaccess.com/cdn-cgi/access/login/sphinx.best?kid=234485d1463af694aa8068356f7af17c0d0e7e825bd0204d50fbe25f3c97bc9c&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6Ijg2OGFmMjMzMzMwYTk2ZmFjNTUzMTBhMmQyN2E2MmQ1ZWM1YWY5Zjg3ZDBhOTg5OTNhMzk0MjZlMDg1NGI2NzcifQ.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.gztjNz7b7okySQWVdw3FqbPtjHv7GBYQhbv03lWeswj0MkAoiOCbwAiDlRJWsJgz2hwJzMQUMOFIRWrRnyQFQjm6R4Z17HIHzwdPXUwpKRrJ9B6uYWUB7W0KtdW49XoGYPzpOGNId_mQElCygNdXWX71eB-17ZXZ8SeW7ZITj7acth55rkhPzWZ-tz7Vxyww3liM6bsXPBJxnUvxJpCGOuemfWfy7_nUELlRWxaNMKmifDHC21NEuBQoQT62HXcOvWXkFBljGeuTgh7flBLnqrxqYOmBx6pc0sXaBRr1VWY2aVXp7alY9Q-O0khoWLDyFN7aZsgHk3Q2SzcLLn_ilw&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/sphinx.best.svg)](https://aaaa.bot/sphinx.best)

Check again

sphinx.best Has IPv6

A (IPv4)	104.21.84.41 172.67.186.22
AAAA (IPv6)	2606:4700:3033::ac43:ba16 2606:4700:3032::6815:5429

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: sphinx.best
Measured 2026-11-03 01:56:46 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    104.21.84.41, 172.67.186.22
AAAA (IPv6): 2606:4700:3033::ac43:ba16, 2606:4700:3032::6815:5429

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: sphinx.best has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3033::ac43:ba16: answers (TCP 443)
    2606:4700:3032::6815:5429: 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://sphinx.best/ via 2606:4700:3033::ac43:ba16 -> HTTP 302, certificate: valid
    https://cool-paper-fbfe.cloudflareaccess.com/cdn-cgi/access/login/sphinx.best?kid=234485d1463af694aa8068356f7af17c0d0e7e825bd0204d50fbe25f3c97bc9c&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6Ijg2OGFmMjMzMzMwYTk2ZmFjNTUzMTBhMmQyN2E2MmQ1ZWM1YWY5Zjg3ZDBhOTg5OTNhMzk0MjZlMDg1NGI2NzcifQ.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.gztjNz7b7okySQWVdw3FqbPtjHv7GBYQhbv03lWeswj0MkAoiOCbwAiDlRJWsJgz2hwJzMQUMOFIRWrRnyQFQjm6R4Z17HIHzwdPXUwpKRrJ9B6uYWUB7W0KtdW49XoGYPzpOGNId_mQElCygNdXWX71eB-17ZXZ8SeW7ZITj7acth55rkhPzWZ-tz7Vxyww3liM6bsXPBJxnUvxJpCGOuemfWfy7_nUELlRWxaNMKmifDHC21NEuBQoQT62HXcOvWXkFBljGeuTgh7flBLnqrxqYOmBx6pc0sXaBRr1VWY2aVXp7alY9Q-O0khoWLDyFN7aZsgHk3Q2SzcLLn_ilw&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/rg2p2DPY_L

Permanent link: aaaa.bot/r/rg2p2DPY_L · How we measure

Checked 2026-11-03 01:56:46 UTC. Full DNS report: dns.pizza/domain/sphinx.best · Age, certificate and blocklists: how.is/sphinx.best · JSON: /api/v1/sphinx.best