Yes — shorturl.at has IPv6.

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

IPv6 readiness

Works over IPv6, with one gap: its mail servers lack IPv6.

Website over IPv6 shorturl.at has 3 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:20::681a:981 answers · 443✓ 2606:4700:20::ac43:4558 answers · 443✓ 2606:4700:20::681a:881 answers · 443	yes
www over IPv6 www.shorturl.at has 3 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:20::681a:881 answers · 443✓ 2606:4700:20::ac43:4558 answers · 443✓ 2606:4700:20::681a:981 answers · 443	yes
Mail servers (MX) have IPv6 None of the mail servers has an AAAA record. mail.shorturl.at ✗	no
Nameservers have IPv6 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. jason.ns.cloudflare.com ✓mia.ns.cloudflare.com ✓	yes

HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate: HTTP 403.

https://shorturl.at/ via 2606:4700:20::681a:981 → 403

works

What's keeping shorturl.at from an A

Mail servers without IPv6
mail.shorturl.at has no AAAA record, so mail from IPv6-only servers can't reach it directly. If a provider runs your mail, that's their setting; if you run it, add AAAA records for these hosts.

Check again

shorturl.at Has IPv6

A (IPv4)	172.67.69.88 104.26.9.129 104.26.8.129
AAAA (IPv6)	2606:4700:20::681a:981 2606:4700:20::ac43:4558 2606:4700:20::681a:881

www.shorturl.at Has IPv6

A (IPv4)	104.26.9.129 104.26.8.129 172.67.69.88
AAAA (IPv6)	2606:4700:20::681a:881 2606:4700:20::ac43:4558 2606:4700:20::681a:981

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: shorturl.at
Measured 2026-11-05 11:03:42 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    172.67.69.88, 104.26.9.129, 104.26.8.129
AAAA (IPv6): 2606:4700:20::681a:981, 2606:4700:20::ac43:4558, 2606:4700:20::681a:881
www AAAA:    2606:4700:20::681a:881, 2606:4700:20::ac43:4558, 2606:4700:20::681a:981

Readiness grade B: Works over IPv6, with one gap: its mail servers lack IPv6.
- Website over IPv6: shorturl.at has 3 IPv6 addresses and answers on every one we tested.
    2606:4700:20::681a:981: answers (TCP 443)
    2606:4700:20::ac43:4558: answers (TCP 443)
    2606:4700:20::681a:881: answers (TCP 443)
- www over IPv6: www.shorturl.at has 3 IPv6 addresses and answers on every one we tested.
    2606:4700:20::681a:881: answers (TCP 443)
    2606:4700:20::ac43:4558: answers (TCP 443)
    2606:4700:20::681a:981: answers (TCP 443)
- Mail servers (MX) have IPv6: None of the mail servers 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 403.
    https://shorturl.at/ via 2606:4700:20::681a:981 -> HTTP 403, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/gOE2t77bwa

Permanent link: aaaa.bot/r/gOE2t77bwa · How we measure

Checked 2026-11-05 11:03:42 UTC. Full DNS report: dns.pizza/domain/shorturl.at · Age, certificate and blocklists: how.is/shorturl.at · JSON: /api/v1/shorturl.at