No — nethost.cz is IPv4 only.

Has an IPv4 address but no IPv6 (AAAA) record. IPv6-only visitors can't reach it directly.

Measured 2026-11-14 19:13 UTC. We reuse a result for up to a week, so we aren't testing the same site over and over. Check nethost.cz now

IPv6 readiness

The website has no IPv6.

Website over IPv6 nethost.cz has no AAAA record.	no
www over IPv6 www.nethost.cz has 3 IPv6 addresses and answers on every one we tested. ✓ 2001:41d0:404:200::86e3 answers · 443✓ 2001:41d0:601:1100::3792 answers · 443✓ 2001:41d0:701:1100::4d2e answers · 443	yes
Mail servers (MX) have IPv6 None of the mail servers has an AAAA record. mail-prox-relay-a3x57.nethost.cz ✗mail-prox-relay-q98d7.nethost.cz ✗	no
Nameservers have IPv6 3 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. dns.nethost.cz ✓pns.nethost.cz ✗sns.nethost.sk ✓tns.nethost.eu ✓	yes

First measured 2026-11-04; last confirmed 2026-11-14.

What's keeping nethost.cz from an A

Give nethost.cz an IPv6 address
Ask your hosting provider for the site's IPv6 address (or the hostname to point at), then publish it as an AAAA record. If your host doesn't offer IPv6, a proxy that does can sit in front. How to add an AAAA record
Mail servers without IPv6
mail-prox-relay-a3x57.nethost.cz, mail-prox-relay-q98d7.nethost.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

nethost.cz IPv4 only

A (IPv4)	93.185.108.254
AAAA (IPv6)	none

www.nethost.cz Has IPv6

Alias of	20781-4d7511c3dcbd55bdf858.spongefinger.com
A (IPv4)	146.59.3.180 51.38.99.173 37.187.45.2
AAAA (IPv6)	2001:41d0:404:200::86e3 2001:41d0:601:1100::3792 2001:41d0:701:1100::4d2e

What this means

Visitors on IPv6-only networks (many mobile carriers) can still reach it, but only through a translator their carrier runs (NAT64). The site itself has no IPv6 address — and you can't make one up from the IPv4. Why some hosts don't offer it

Copy the evidence — a citation-ready record of this measurement

IPv6 measurement: nethost.cz
Measured 2026-11-14 19:13:56 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    93.185.108.254
AAAA (IPv6): none
www AAAA:    2001:41d0:404:200::86e3, 2001:41d0:601:1100::3792, 2001:41d0:701:1100::4d2e

Readiness grade D: The website has no IPv6.
- Website over IPv6: nethost.cz has no AAAA record.
- www over IPv6: www.nethost.cz has 3 IPv6 addresses and answers on every one we tested.
    2001:41d0:404:200::86e3: answers (TCP 443)
    2001:41d0:601:1100::3792: answers (TCP 443)
    2001:41d0:701:1100::4d2e: answers (TCP 443)
- Mail servers (MX) have IPv6: None of the mail servers has an AAAA record.
- Nameservers have IPv6: 3 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).
No TLS or HTTP request was made.
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/hek5PjBJmC

Permanent link: aaaa.bot/r/hek5PjBJmC · How we measure

Checked 2026-11-14 19:13:56 UTC. Full DNS report: dns.pizza/domain/nethost.cz · Age, certificate and blocklists: how.is/nethost.cz · JSON: /api/v1/nethost.cz