Yes — tandem.science has IPv6.

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

A
IPv6 readiness
Website, mail and DNS all work over IPv6.
Website over IPv6
tandem.science has 2 IPv6 addresses and answers on every one we tested.
✓ 2606:4700:3034::6815:2f32 answers · 443✓ 2606:4700:3035::ac43:908b answers · 443
yes
Mail servers (MX) have IPv6
No MX records, so mail goes to the domain's own address (implicit MX). It has an AAAA record.		yes
Nameservers have IPv6
2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.
alla.ns.cloudflare.com ✓ned.ns.cloudflare.com ✓
yes
HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate: HTTP 200.
https://tandem.science/ via 2606:4700:3034::6815:2f32 → 200
works
 Which outside scripts, fonts, payments or chat tandem.science loads from have no IPv6.
 Load tandem.science over IPv6 from up to six other places — a second opinion.

Nothing keeping you from an A

  1. Nothing to fix
    Show it off: add the badge to your README.
    [![IPv6](https://aaaa.bot/badge/tandem.science.svg)](https://aaaa.bot/tandem.science)

Check again

tandem.science  Has IPv6

A (IPv4)172.67.144.139
104.21.47.50
AAAA (IPv6)2606:4700:3034::6815:2f32
2606:4700:3035::ac43:908b

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/0dNJQgju9E · How we measure

Checked 2026-11-09 00:43:04 UTC. Full DNS report: dns.pizza/domain/tandem.science · Age, certificate and blocklists: how.is/tandem.science · JSON: /api/v1/tandem.science