Yes — onlineshop.cz 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 onlineshop.cz has 3 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:20::681a:227 answers · 443✓ 2606:4700:20::681a:327 answers · 443✓ 2606:4700:20::ac43:493b answers · 443	yes
www over IPv6 www.onlineshop.cz has 3 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:20::681a:227 answers · 443✓ 2606:4700:20::681a:327 answers · 443✓ 2606:4700:20::ac43:493b answers · 443	yes
Mail servers (MX) have IPv6 None of the mail servers has an AAAA record. kokes.shosting.cz ✗ns2.shosting.cz ✗	no
Nameservers have IPv6 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. brady.ns.cloudflare.com ✓journey.ns.cloudflare.com ✓	yes

First measured 2026-11-04; last confirmed 2026-11-04.

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

https://onlineshop.cz/ via 2606:4700:20::681a:227 → 301https://www.onlineshop.cz/ via 2606:4700:20::681a:227 → 200

works

What's keeping onlineshop.cz from an A

Mail servers without IPv6
kokes.shosting.cz, ns2.shosting.cz have no AAAA record, so mail from IPv6-only servers can't reach them directly. If a provider runs your mail, that's their setting; if you run it, add AAAA records for these hosts.

Check again

onlineshop.cz Has IPv6

A (IPv4)	104.26.2.39 104.26.3.39 172.67.73.59
AAAA (IPv6)	2606:4700:20::681a:227 2606:4700:20::681a:327 2606:4700:20::ac43:493b

www.onlineshop.cz Has IPv6

A (IPv4)	104.26.3.39 172.67.73.59 104.26.2.39
AAAA (IPv6)	2606:4700:20::681a:227 2606:4700:20::681a:327 2606:4700:20::ac43:493b

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: onlineshop.cz
Measured 2026-11-15 15:50:38 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    104.26.2.39, 104.26.3.39, 172.67.73.59
AAAA (IPv6): 2606:4700:20::681a:227, 2606:4700:20::681a:327, 2606:4700:20::ac43:493b
www AAAA:    2606:4700:20::681a:227, 2606:4700:20::681a:327, 2606:4700:20::ac43:493b

Readiness grade B: Works over IPv6, with one gap: its mail servers lack IPv6.
- Website over IPv6: onlineshop.cz has 3 IPv6 addresses and answers on every one we tested.
    2606:4700:20::681a:227: answers (TCP 443)
    2606:4700:20::681a:327: answers (TCP 443)
    2606:4700:20::ac43:493b: answers (TCP 443)
- www over IPv6: www.onlineshop.cz has 3 IPv6 addresses and answers on every one we tested.
    2606:4700:20::681a:227: answers (TCP 443)
    2606:4700:20::681a:327: answers (TCP 443)
    2606:4700:20::ac43:493b: 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 after 1 redirect: HTTP 200.
    https://onlineshop.cz/ via 2606:4700:20::681a:227 -> HTTP 301, certificate: valid
    https://www.onlineshop.cz/ via 2606:4700:20::681a:227 -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/PiQ99Hwf6S

Permanent link: aaaa.bot/r/PiQ99Hwf6S · How we measure

Checked 2026-11-15 15:50:38 UTC. Full DNS report: dns.pizza/domain/onlineshop.cz · Age, certificate and blocklists: how.is/onlineshop.cz · JSON: /api/v1/onlineshop.cz