Yes — ratracelabs.dev has IPv6.

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

IPv6 readiness

Works over IPv6, with one gap: www doesn't fully work over IPv6.

Website over IPv6 ratracelabs.dev has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3032::6815:4de3 answers · 443✓ 2606:4700:3035::ac43:d423 answers · 443	yes
www over IPv6 www.ratracelabs.dev has no AAAA record.	no
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. lily.ns.cloudflare.com ✓gordon.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://ratracelabs.dev/ via 2606:4700:3032::6815:4de3 → 302https://benevolus.cloudflareaccess.com/cdn-cgi/access/login/ratracelabs.dev?kid=57c1ac670d27547e3cfb72919d1fa181c1751c3a8c7c76fb1321af9242481ad4&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6ImJlMTQ2ZWNmODAyNWQxMjU5NTY4M2MwYjI5YzJlZjM3NGNiNDIzZDNjMDczM2JjYTk1YTAwYzk1OWE1YzJlMGYifQ.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.HGbLmASDOvyRIMX2k9JwC8D-WlfftKJuVZ76CZXGLsn8ldesjqqt30-xDj7DKjHsnZ8uXDyfev0I1kPzo-q7vk1ySsCx4FM2cb7ZHBNa3bE_bma2OniLJIgJG_DpmkctM5KplB3so-pQbJb6yv-w3Man3ltB4ZSfR1vDliSa6Iwg0FeOntHtgzf5kKlMDrt5lcMIz-CwjlRNhBcNko6CtjuomR9SQPf2_q2--R7sYNIizVlunT2G44jVKDChtDUsDY6D5UDrC0bmYFiQ733QIB9BISLyoPXdSQO9lNu4cg_JgcWBePDSAvU0xNYs6iKDXU2vCkoKZFNipXPQudzTog&redirect_url=%2F via 2606:4700:300a::6813:c21d → 200

works

What's keeping ratracelabs.dev from an A

Add IPv6 for www.ratracelabs.dev
www.ratracelabs.dev has no AAAA record. Get www's IPv6 address from whoever hosts www and add it as an AAAA record. If the same server already serves both names (and its certificate covers www), you can reuse ratracelabs.dev's AAAA record(s) for www. How to add an AAAA record

Check again

ratracelabs.dev Has IPv6

A (IPv4)	104.21.77.227 172.67.212.35
AAAA (IPv6)	2606:4700:3032::6815:4de3 2606:4700:3035::ac43:d423

www.ratracelabs.dev No address

A (IPv4)	none
AAAA (IPv6)	none

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: ratracelabs.dev
Measured 2026-11-11 06:30:08 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    104.21.77.227, 172.67.212.35
AAAA (IPv6): 2606:4700:3032::6815:4de3, 2606:4700:3035::ac43:d423
www AAAA:    none

Readiness grade B: Works over IPv6, with one gap: www doesn't fully work over IPv6.
- Website over IPv6: ratracelabs.dev has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3032::6815:4de3: answers (TCP 443)
    2606:4700:3035::ac43:d423: answers (TCP 443)
- www over IPv6: www.ratracelabs.dev has no AAAA record.
- 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://ratracelabs.dev/ via 2606:4700:3032::6815:4de3 -> HTTP 302, certificate: valid
    https://benevolus.cloudflareaccess.com/cdn-cgi/access/login/ratracelabs.dev?kid=57c1ac670d27547e3cfb72919d1fa181c1751c3a8c7c76fb1321af9242481ad4&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6ImJlMTQ2ZWNmODAyNWQxMjU5NTY4M2MwYjI5YzJlZjM3NGNiNDIzZDNjMDczM2JjYTk1YTAwYzk1OWE1YzJlMGYifQ.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.HGbLmASDOvyRIMX2k9JwC8D-WlfftKJuVZ76CZXGLsn8ldesjqqt30-xDj7DKjHsnZ8uXDyfev0I1kPzo-q7vk1ySsCx4FM2cb7ZHBNa3bE_bma2OniLJIgJG_DpmkctM5KplB3so-pQbJb6yv-w3Man3ltB4ZSfR1vDliSa6Iwg0FeOntHtgzf5kKlMDrt5lcMIz-CwjlRNhBcNko6CtjuomR9SQPf2_q2--R7sYNIizVlunT2G44jVKDChtDUsDY6D5UDrC0bmYFiQ733QIB9BISLyoPXdSQO9lNu4cg_JgcWBePDSAvU0xNYs6iKDXU2vCkoKZFNipXPQudzTog&redirect_url=%2F via 2606:4700:300a::6813:c21d -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/3Zsqj44nVN

Permanent link: aaaa.bot/r/3Zsqj44nVN · How we measure

Checked 2026-11-11 06:30:08 UTC. Full DNS report: dns.pizza/domain/ratracelabs.dev · Age, certificate and blocklists: how.is/ratracelabs.dev · JSON: /api/v1/ratracelabs.dev