Yes — docker.io has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 docker.io has 3 IPv6 addresses and answers on every one we tested. ✓ 2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9 answers · 443✓ 2600:1f18:2148:bc00:eb39:1baf:a9b:8d58 answers · 443✓ 2600:1f18:2148:bc02:dd71:3e03:179:5785 answers · 443	yes
www over IPv6 www.docker.io has 3 IPv6 addresses and answers on every one we tested. ✓ 2600:1f18:2148:bc02:dd71:3e03:179:5785 answers · 443✓ 2600:1f18:2148:bc00:eb39:1baf:a9b:8d58 answers · 443✓ 2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9 answers · 443	yes
Mail servers (MX) have IPv6 Every mail server has an AAAA record. aspmx.l.google.com ✓alt1.aspmx.l.google.com ✓aspmx2.googlemail.com ✓aspmx3.googlemail.com ✓aspmx4.googlemail.com ✓aspmx5.googlemail.com ✓	yes
Nameservers have IPv6 4 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. ns-1168.awsdns-18.org ✓ns-1827.awsdns-36.co.uk ✓ns-421.awsdns-52.com ✓ns-513.awsdns-00.net ✓	yes

HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate after 1 redirect: HTTP 200.

https://docker.io/ via 2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9 → 302https://www.docker.com/ via 2620:12a:8000::4 → 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/docker.io.svg)](https://aaaa.bot/docker.io)

Check again

docker.io Has IPv6

A (IPv4)	54.163.166.73 32.193.181.249 32.200.67.23
AAAA (IPv6)	2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9 2600:1f18:2148:bc00:eb39:1baf:a9b:8d58 2600:1f18:2148:bc02:dd71:3e03:179:5785

www.docker.io Has IPv6

Alias of	elb-io.us-east-1.aws.dckr.io
A (IPv4)	32.200.67.23 32.193.181.249 54.163.166.73
AAAA (IPv6)	2600:1f18:2148:bc02:dd71:3e03:179:5785 2600:1f18:2148:bc00:eb39:1baf:a9b:8d58 2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9

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: docker.io
Measured 2026-10-31 20:41:33 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    54.163.166.73, 32.193.181.249, 32.200.67.23
AAAA (IPv6): 2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9, 2600:1f18:2148:bc00:eb39:1baf:a9b:8d58, 2600:1f18:2148:bc02:dd71:3e03:179:5785
www AAAA:    2600:1f18:2148:bc02:dd71:3e03:179:5785, 2600:1f18:2148:bc00:eb39:1baf:a9b:8d58, 2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: docker.io has 3 IPv6 addresses and answers on every one we tested.
    2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9: answers (TCP 443)
    2600:1f18:2148:bc00:eb39:1baf:a9b:8d58: answers (TCP 443)
    2600:1f18:2148:bc02:dd71:3e03:179:5785: answers (TCP 443)
- www over IPv6: www.docker.io has 3 IPv6 addresses and answers on every one we tested.
    2600:1f18:2148:bc02:dd71:3e03:179:5785: answers (TCP 443)
    2600:1f18:2148:bc00:eb39:1baf:a9b:8d58: answers (TCP 443)
    2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9: answers (TCP 443)
- Mail servers (MX) have IPv6: Every mail server 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 after 1 redirect: HTTP 200.
    https://docker.io/ via 2600:1f18:2148:bc01:8ace:b487:fcc3:4aa9 -> HTTP 302, certificate: valid
    https://www.docker.com/ via 2620:12a:8000::4 -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/VDmu-JVAjC

Permanent link: aaaa.bot/r/VDmu-JVAjC · How we measure

Checked 2026-10-31 20:41:33 UTC. Full DNS report: dns.pizza/domain/docker.io · JSON: /api/v1/docker.io