Yes — eslack.website has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 eslack.website has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3037::ac43:a1c0 answers · 443✓ 2606:4700:3031::6815:f3d answers · 443	yes
www over IPv6 www.eslack.website has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3031::6815:f3d answers · 443✓ 2606:4700:3037::ac43:a1c0 answers · 443	yes
Mail servers (MX) have IPv6 Every mail server has an AAAA record. route3.mx.cloudflare.net ✓route2.mx.cloudflare.net ✓route1.mx.cloudflare.net ✓	yes
Nameservers have IPv6 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. cartman.ns.cloudflare.com ✓desiree.ns.cloudflare.com ✓	yes

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

https://eslack.website/ via 2606:4700:3037::ac43:a1c0 → 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/eslack.website.svg)](https://aaaa.bot/eslack.website)

Check again

eslack.website Has IPv6

A (IPv4)	104.21.15.61 172.67.161.192
AAAA (IPv6)	2606:4700:3037::ac43:a1c0 2606:4700:3031::6815:f3d

www.eslack.website Has IPv6

A (IPv4)	172.67.161.192 104.21.15.61
AAAA (IPv6)	2606:4700:3031::6815:f3d 2606:4700:3037::ac43:a1c0

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: eslack.website
Measured 2026-11-07 21:42:27 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    104.21.15.61, 172.67.161.192
AAAA (IPv6): 2606:4700:3037::ac43:a1c0, 2606:4700:3031::6815:f3d
www AAAA:    2606:4700:3031::6815:f3d, 2606:4700:3037::ac43:a1c0

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: eslack.website has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3037::ac43:a1c0: answers (TCP 443)
    2606:4700:3031::6815:f3d: answers (TCP 443)
- www over IPv6: www.eslack.website has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3031::6815:f3d: answers (TCP 443)
    2606:4700:3037::ac43:a1c0: answers (TCP 443)
- Mail servers (MX) have IPv6: Every mail server 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: HTTP 200.
    https://eslack.website/ via 2606:4700:3037::ac43:a1c0 -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/QfYnAsmNsS

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

Checked 2026-11-07 21:42:27 UTC. Full DNS report: dns.pizza/domain/eslack.website · Age, certificate and blocklists: how.is/eslack.website · JSON: /api/v1/eslack.website