Yes — ck-ledger.app has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 ck-ledger.app has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3035::6815:74b answers · 443✓ 2606:4700:3031::ac43:87cd 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. mario.ns.cloudflare.com ✓nelly.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://ck-ledger.app/ via 2606:4700:3035::6815:74b → 302https://white-dingo19.cloudflareaccess.com/cdn-cgi/access/login/ck-ledger.app?kid=73d50a55b74057290b75ec4a1208ce2d2fe5f6346b69a8f15776d8e675244e2e&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6ImRmZjc0OTRkZDhiMGIxYjVhYTI5ZDAzODMwMzZjMDQ5ZWRlNjUwYjUzMmRjYWMyZjEzMTgzZGY2OTVkNTFiN2QifQ.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.AbyhCsbTcUwJQ1wP0LoRkWAfjEzYD9gbOtN3YZoHMgW_0J9cGMfti3Fo7iq4SS5QDPIaNxc5mAOF4NDQNQqBuvDzEYdbVypWBQO-whGvMVJbPDae7bkYy2DbMuIH2LcxrXot_rLThZ-XFL1v0I9VRW9ZxOyZmDiqr310kXHDFXWOlyBzXoyC6qeWxZ156iCiHZRgc9wj8WDHEhBocV8lU2Q6Uk3H0Ui4P-1hTvO410Ck6xWPdOnx-rSIDkb3Ijrd-oCpzrvhyhOV0hqoIjgfewCIWeJtwcL9lc-gVltuNPIFvyTXriXUkuJ9rkcE5MCtdvAy-i062JgF1ne45lUFpg&redirect_url=%2F via 2606:4700:300a::6813:c21d → 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/ck-ledger.app.svg)](https://aaaa.bot/ck-ledger.app)

Check again

ck-ledger.app Has IPv6

A (IPv4)	172.67.135.205 104.21.7.75
AAAA (IPv6)	2606:4700:3035::6815:74b 2606:4700:3031::ac43:87cd

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: ck-ledger.app
Measured 2026-11-11 20:59:25 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    172.67.135.205, 104.21.7.75
AAAA (IPv6): 2606:4700:3035::6815:74b, 2606:4700:3031::ac43:87cd

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: ck-ledger.app has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3035::6815:74b: answers (TCP 443)
    2606:4700:3031::ac43:87cd: 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://ck-ledger.app/ via 2606:4700:3035::6815:74b -> HTTP 302, certificate: valid
    https://white-dingo19.cloudflareaccess.com/cdn-cgi/access/login/ck-ledger.app?kid=73d50a55b74057290b75ec4a1208ce2d2fe5f6346b69a8f15776d8e675244e2e&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6ImRmZjc0OTRkZDhiMGIxYjVhYTI5ZDAzODMwMzZjMDQ5ZWRlNjUwYjUzMmRjYWMyZjEzMTgzZGY2OTVkNTFiN2QifQ.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.AbyhCsbTcUwJQ1wP0LoRkWAfjEzYD9gbOtN3YZoHMgW_0J9cGMfti3Fo7iq4SS5QDPIaNxc5mAOF4NDQNQqBuvDzEYdbVypWBQO-whGvMVJbPDae7bkYy2DbMuIH2LcxrXot_rLThZ-XFL1v0I9VRW9ZxOyZmDiqr310kXHDFXWOlyBzXoyC6qeWxZ156iCiHZRgc9wj8WDHEhBocV8lU2Q6Uk3H0Ui4P-1hTvO410Ck6xWPdOnx-rSIDkb3Ijrd-oCpzrvhyhOV0hqoIjgfewCIWeJtwcL9lc-gVltuNPIFvyTXriXUkuJ9rkcE5MCtdvAy-i062JgF1ne45lUFpg&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/4M5Kl_3zaY

Permanent link: aaaa.bot/r/4M5Kl_3zaY · How we measure

Checked 2026-11-11 20:59:25 UTC. Full DNS report: dns.pizza/domain/ck-ledger.app · Age, certificate and blocklists: how.is/ck-ledger.app · JSON: /api/v1/ck-ledger.app