No — sas.ac.uk is IPv4 only.

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

IPv6 readiness

The website has no IPv6.

Website over IPv6 sas.ac.uk has no AAAA record.	no
www over IPv6 www.sas.ac.uk has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:10::6814:2cf2 answers · 443✓ 2606:4700:10::ac42:9daa answers · 443	yes
Mail servers (MX) have IPv6 Every mail server has an AAAA record. sas-ac-uk.mail.protection.outlook.com ✓	yes
Nameservers have IPv6 No nameserver has an AAAA record — an IPv6-only resolver can't reach this domain's DNS. dns-ns1.ucl.ac.uk ✗ns0.ulcc.ac.uk ✗ns1.ulcc.ac.uk ✗dns-ns0.ucl.ac.uk ✗	no

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

What's keeping sas.ac.uk from an A

Give sas.ac.uk 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
Nameservers without IPv6
dns-ns1.ucl.ac.uk, ns0.ulcc.ac.uk, ns1.ulcc.ac.uk, dns-ns0.ucl.ac.uk all have no AAAA record, so a resolver that only speaks IPv6 can't look your domain up. Most DNS providers offer IPv6 nameservers; ask yours, or move DNS to one that does.

Check again

sas.ac.uk IPv4 only

A (IPv4)	51.132.32.57
AAAA (IPv6)	none

www.sas.ac.uk Has IPv6

Alias of	www.sas.ac.uk.cdn.cloudflare.net
A (IPv4)	104.20.44.242 172.66.157.170
AAAA (IPv6)	2606:4700:10::6814:2cf2 2606:4700:10::ac42:9daa

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: sas.ac.uk
Measured 2026-11-15 16:30:11 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    51.132.32.57
AAAA (IPv6): none
www AAAA:    2606:4700:10::6814:2cf2, 2606:4700:10::ac42:9daa

Readiness grade D: The website has no IPv6.
- Website over IPv6: sas.ac.uk has no AAAA record.
- www over IPv6: www.sas.ac.uk has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:10::6814:2cf2: answers (TCP 443)
    2606:4700:10::ac42:9daa: answers (TCP 443)
- Mail servers (MX) have IPv6: Every mail server has an AAAA record.
- Nameservers have IPv6: No nameserver has an AAAA record — an IPv6-only resolver can't reach this domain's DNS.

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/B6bRcVnP1D

Permanent link: aaaa.bot/r/B6bRcVnP1D · How we measure

Checked 2026-11-15 16:30:11 UTC. Full DNS report: dns.pizza/domain/sas.ac.uk · Age, certificate and blocklists: how.is/sas.ac.uk · JSON: /api/v1/sas.ac.uk