Yes — docs.posthog.com has IPv6.

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

B
IPv6 readiness
Works over IPv6, with one gap: www doesn't fully work over IPv6.
Website over IPv6
docs.posthog.com has 2 IPv6 addresses and answers on every one we tested.
✓ 2606:4700:10::6814:11a7 answers · 443✓ 2606:4700:10::ac42:a6a4 answers · 443
yes
www over IPv6
www.docs.posthog.com has no AAAA record.		no
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.
rory.ns.cloudflare.com ✓julissa.ns.cloudflare.com ✓
yes
HTTPS over IPv6 · not part of the grade yet
Redirects to posthog.com, which has no IPv6 address — so IPv6 visitors end up needing IPv4 after all.
https://docs.posthog.com/ via 2606:4700:10::6814:11a7 → 301https://posthog.com/docs · redirects to posthog.com, which has no IPv6 address
problem
 Load docs.posthog.com over IPv6 from up to six other places — a second opinion.

What's keeping docs.posthog.com from an A

  1. Add IPv6 for www.docs.posthog.com
    www.docs.posthog.com has no AAAA record. Get www's IPv6 address from whoever hosts www and add it as an AAAA record. If the same server already serves both names (and its certificate covers www), you can reuse docs.posthog.com's AAAA record(s) for www. How to add an AAAA record
  2. A redirect leads off IPv6
    Redirects to posthog.com, which has no IPv6 address — so IPv6 visitors end up needing IPv4 after all. Give the redirect target IPv6 too, or redirect somewhere that has it.

Check again

docs.posthog.com  Has IPv6

A (IPv4)104.20.17.167
172.66.166.164
AAAA (IPv6)2606:4700:10::6814:11a7
2606:4700:10::ac42:a6a4

www.docs.posthog.com  No address

A (IPv4)none
AAAA (IPv6)none

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/pZL4KF_joI · How we measure

Checked 2026-11-01 23:03:02 UTC. Full DNS report: dns.pizza/domain/docs.posthog.com · JSON: /api/v1/docs.posthog.com