Yes — simplecapitalone.com has IPv6.

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

B
IPv6 readiness
Works over IPv6, with one gap: its mail servers lack IPv6.
Website over IPv6
simplecapitalone.com has 2 IPv6 addresses and answers on every one we tested.
✓ 2606:4700:3035::ac43:c153 answers · 443✓ 2606:4700:3031::6815:5484 answers · 443
yes
Mail servers (MX) have IPv6
None of the mail servers has an AAAA record.
mx00.ionos.com ✗mx01.ionos.com ✗
no
Nameservers have IPv6
2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.
coraline.ns.cloudflare.com ✓ivan.ns.cloudflare.com ✓
yes
HTTPS over IPv6 · not part of the grade yet
Answered over IPv6 with a server error (HTTP 525) — can't tell whether that's specific to IPv6.
https://simplecapitalone.com/ via 2606:4700:3035::ac43:c153 → 525
?
 Which outside scripts, fonts, payments or chat simplecapitalone.com loads from have no IPv6.
 Load simplecapitalone.com over IPv6 from up to six other places — a second opinion.

What's keeping simplecapitalone.com from an A

  1. Mail servers without IPv6
    mx00.ionos.com, mx01.ionos.com 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

simplecapitalone.com  Has IPv6

A (IPv4)172.67.193.83
104.21.84.132
AAAA (IPv6)2606:4700:3035::ac43:c153
2606:4700:3031::6815:5484

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

 Permanent link: aaaa.bot/r/H6SYcxAvPv · How we measure

Checked 2026-11-06 01:29:04 UTC. Full DNS report: dns.pizza/domain/simplecapitalone.com · Age, certificate and blocklists: how.is/simplecapitalone.com · JSON: /api/v1/simplecapitalone.com