Yes — kotoko.app has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 kotoko.app has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3030::6815:27ec answers · 443✓ 2606:4700:3037::ac43:abd7 answers · 443	yes
www over IPv6 www.kotoko.app has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3037::ac43:abd7 answers · 443✓ 2606:4700:3030::6815:27ec answers · 443	yes
Mail servers (MX) have IPv6 Every mail server has an AAAA record. aspmx.l.google.com ✓alt3.aspmx.l.google.com ✓alt4.aspmx.l.google.com ✓alt1.aspmx.l.google.com ✓alt2.aspmx.l.google.com ✓	yes
Nameservers have IPv6 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. faye.ns.cloudflare.com ✓rudy.ns.cloudflare.com ✓	yes

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

https://kotoko.app/ via 2606:4700:3030::6815:27ec → 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/kotoko.app.svg)](https://aaaa.bot/kotoko.app)

Check again

kotoko.app Has IPv6

A (IPv4)	172.67.171.215 104.21.39.236
AAAA (IPv6)	2606:4700:3030::6815:27ec 2606:4700:3037::ac43:abd7

www.kotoko.app Has IPv6

A (IPv4)	104.21.39.236 172.67.171.215
AAAA (IPv6)	2606:4700:3037::ac43:abd7 2606:4700:3030::6815:27ec

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: kotoko.app
Measured 2026-11-04 04:15:09 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    172.67.171.215, 104.21.39.236
AAAA (IPv6): 2606:4700:3030::6815:27ec, 2606:4700:3037::ac43:abd7
www AAAA:    2606:4700:3037::ac43:abd7, 2606:4700:3030::6815:27ec

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: kotoko.app has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3030::6815:27ec: answers (TCP 443)
    2606:4700:3037::ac43:abd7: answers (TCP 443)
- www over IPv6: www.kotoko.app has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3037::ac43:abd7: answers (TCP 443)
    2606:4700:3030::6815:27ec: 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://kotoko.app/ via 2606:4700:3030::6815:27ec -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/6pUyiOJYqM

Permanent link: aaaa.bot/r/6pUyiOJYqM · How we measure

Checked 2026-11-04 04:15:09 UTC. Full DNS report: dns.pizza/domain/kotoko.app · Age, certificate and blocklists: how.is/kotoko.app · JSON: /api/v1/kotoko.app