Yes — system-lhr.fyi has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 system-lhr.fyi has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3034::6815:12ec answers · 443✓ 2606:4700:3031::ac43:b7e5 answers · 443	yes
www over IPv6 www.system-lhr.fyi has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3031::ac43:b7e5 answers · 443✓ 2606:4700:3034::6815:12ec 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. henrik.ns.cloudflare.com ✓tegan.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://system-lhr.fyi/ via 2606:4700:3034::6815:12ec → 302https://system-lhr.fyi/login via 2606:4700:3034::6815:12ec → 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/system-lhr.fyi.svg)](https://aaaa.bot/system-lhr.fyi)

Check again

system-lhr.fyi Has IPv6

A (IPv4)	172.67.183.229 104.21.18.236
AAAA (IPv6)	2606:4700:3034::6815:12ec 2606:4700:3031::ac43:b7e5

www.system-lhr.fyi Has IPv6

A (IPv4)	104.21.18.236 172.67.183.229
AAAA (IPv6)	2606:4700:3031::ac43:b7e5 2606:4700:3034::6815:12ec

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: system-lhr.fyi
Measured 2026-11-07 04:49:43 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    172.67.183.229, 104.21.18.236
AAAA (IPv6): 2606:4700:3034::6815:12ec, 2606:4700:3031::ac43:b7e5
www AAAA:    2606:4700:3031::ac43:b7e5, 2606:4700:3034::6815:12ec

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: system-lhr.fyi has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3034::6815:12ec: answers (TCP 443)
    2606:4700:3031::ac43:b7e5: answers (TCP 443)
- www over IPv6: www.system-lhr.fyi has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3031::ac43:b7e5: answers (TCP 443)
    2606:4700:3034::6815:12ec: 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://system-lhr.fyi/ via 2606:4700:3034::6815:12ec -> HTTP 302, certificate: valid
    https://system-lhr.fyi/login via 2606:4700:3034::6815:12ec -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/GaGXsBWrkn

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

Checked 2026-11-07 04:49:43 UTC. Full DNS report: dns.pizza/domain/system-lhr.fyi · Age, certificate and blocklists: how.is/system-lhr.fyi · JSON: /api/v1/system-lhr.fyi