Yes — app.link has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 app.link has 4 IPv6 addresses and answers on every one we tested (4 more not tested). ✓ 2600:9000:28a0:4e00:19:9934:6a80:93a1 answers · 443✓ 2600:9000:28a0:3e00:19:9934:6a80:93a1 answers · 443✓ 2600:9000:28a0:ca00:19:9934:6a80:93a1 answers · 443✓ 2600:9000:28a0:a400:19:9934:6a80:93a1 answers · 443– 2600:9000:28a0:5800:19:9934:6a80:93a1 not tested– 2600:9000:28a0:dc00:19:9934:6a80:93a1 not tested– 2600:9000:28a0:9400:19:9934:6a80:93a1 not tested– 2600:9000:28a0:9000:19:9934:6a80:93a1 not tested	yes
www over IPv6 www.app.link has 4 IPv6 addresses and answers on every one we tested (4 more not tested). ✓ 2600:9000:28a0:4800:19:9934:6a80:93a1 answers · 443✓ 2600:9000:28a0:e000:19:9934:6a80:93a1 answers · 443✓ 2600:9000:28a0:7000:19:9934:6a80:93a1 answers · 443✓ 2600:9000:28a0:c600:19:9934:6a80:93a1 answers · 443– 2600:9000:28a0:3400:19:9934:6a80:93a1 not tested– 2600:9000:28a0:ac00:19:9934:6a80:93a1 not tested– 2600:9000:28a0:4200:19:9934:6a80:93a1 not tested– 2600:9000:28a0:dc00:19:9934:6a80:93a1 not tested	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 4 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. ns-1521.awsdns-62.org ✓ns-1800.awsdns-33.co.uk ✓ns-249.awsdns-31.com ✓ns-615.awsdns-12.net ✓	yes

HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate: HTTP 404.

https://app.link/ via 2600:9000:28a0:4e00:19:9934:6a80:93a1 → 404

works

Nothing keeping you from an A

Nothing to fix
Show it off: add the badge to your README.
[![IPv6](https://aaaa.bot/badge/app.link.svg)](https://aaaa.bot/app.link)

Check again

app.link Has IPv6

A (IPv4)	3.171.38.47 3.171.38.40 3.171.38.89 3.171.38.74
AAAA (IPv6)	2600:9000:28a0:4e00:19:9934:6a80:93a1 2600:9000:28a0:3e00:19:9934:6a80:93a1 2600:9000:28a0:ca00:19:9934:6a80:93a1 2600:9000:28a0:a400:19:9934:6a80:93a1 2600:9000:28a0:5800:19:9934:6a80:93a1 2600:9000:28a0:dc00:19:9934:6a80:93a1 2600:9000:28a0:9400:19:9934:6a80:93a1 2600:9000:28a0:9000:19:9934:6a80:93a1

www.app.link Has IPv6

A (IPv4)	3.171.38.89 3.171.38.40 3.171.38.47 3.171.38.74
AAAA (IPv6)	2600:9000:28a0:4800:19:9934:6a80:93a1 2600:9000:28a0:e000:19:9934:6a80:93a1 2600:9000:28a0:7000:19:9934:6a80:93a1 2600:9000:28a0:c600:19:9934:6a80:93a1 2600:9000:28a0:3400:19:9934:6a80:93a1 2600:9000:28a0:ac00:19:9934:6a80:93a1 2600:9000:28a0:4200:19:9934:6a80:93a1 2600:9000:28a0:dc00:19:9934:6a80:93a1

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: app.link
Measured 2026-11-01 12:15:42 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    3.171.38.47, 3.171.38.40, 3.171.38.89, 3.171.38.74
AAAA (IPv6): 2600:9000:28a0:4e00:19:9934:6a80:93a1, 2600:9000:28a0:3e00:19:9934:6a80:93a1, 2600:9000:28a0:ca00:19:9934:6a80:93a1, 2600:9000:28a0:a400:19:9934:6a80:93a1, 2600:9000:28a0:5800:19:9934:6a80:93a1, 2600:9000:28a0:dc00:19:9934:6a80:93a1, 2600:9000:28a0:9400:19:9934:6a80:93a1, 2600:9000:28a0:9000:19:9934:6a80:93a1
www AAAA:    2600:9000:28a0:4800:19:9934:6a80:93a1, 2600:9000:28a0:e000:19:9934:6a80:93a1, 2600:9000:28a0:7000:19:9934:6a80:93a1, 2600:9000:28a0:c600:19:9934:6a80:93a1, 2600:9000:28a0:3400:19:9934:6a80:93a1, 2600:9000:28a0:ac00:19:9934:6a80:93a1, 2600:9000:28a0:4200:19:9934:6a80:93a1, 2600:9000:28a0:dc00:19:9934:6a80:93a1

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: app.link has 4 IPv6 addresses and answers on every one we tested (4 more not tested).
    2600:9000:28a0:4e00:19:9934:6a80:93a1: answers (TCP 443)
    2600:9000:28a0:3e00:19:9934:6a80:93a1: answers (TCP 443)
    2600:9000:28a0:ca00:19:9934:6a80:93a1: answers (TCP 443)
    2600:9000:28a0:a400:19:9934:6a80:93a1: answers (TCP 443)
    2600:9000:28a0:5800:19:9934:6a80:93a1: not tested
    2600:9000:28a0:dc00:19:9934:6a80:93a1: not tested
    2600:9000:28a0:9400:19:9934:6a80:93a1: not tested
    2600:9000:28a0:9000:19:9934:6a80:93a1: not tested
- www over IPv6: www.app.link has 4 IPv6 addresses and answers on every one we tested (4 more not tested).
    2600:9000:28a0:4800:19:9934:6a80:93a1: answers (TCP 443)
    2600:9000:28a0:e000:19:9934:6a80:93a1: answers (TCP 443)
    2600:9000:28a0:7000:19:9934:6a80:93a1: answers (TCP 443)
    2600:9000:28a0:c600:19:9934:6a80:93a1: answers (TCP 443)
    2600:9000:28a0:3400:19:9934:6a80:93a1: not tested
    2600:9000:28a0:ac00:19:9934:6a80:93a1: not tested
    2600:9000:28a0:4200:19:9934:6a80:93a1: not tested
    2600:9000:28a0:dc00:19:9934:6a80:93a1: not tested
- 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: 4 of 4 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 404.
    https://app.link/ via 2600:9000:28a0:4e00:19:9934:6a80:93a1 -> HTTP 404, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/V1-b79K7yp

Permanent link: aaaa.bot/r/V1-b79K7yp · How we measure

Checked 2026-11-01 12:15:42 UTC. Full DNS report: dns.pizza/domain/app.link · JSON: /api/v1/app.link