Yes — fb.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
fb.com has an AAAA record and answers on it.
✓ 2a03:2880:f373:1:face:b00c:0:25de answers · 443
yes
www over IPv6
www.fb.com has an AAAA record and answers on it.
✓ 2a03:2880:f381:1:face:b00c:0:25de answers · 443
yes
Mail servers (MX) have IPv6
None of the mail servers has an AAAA record.
mxa-00082601.gslb.pphosted.com ✗mx0a-00082601.pphosted.com ✗mx0b-00082601.pphosted.com ✗mxb-00082601.gslb.pphosted.com ✗
no
Nameservers have IPv6
4 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.
c.ns.facebook.com ✓d.ns.facebook.com ✓b.ns.facebook.com ✓a.ns.facebook.com ✓
yes
HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate after 1 redirect: HTTP 200.
https://fb.com/ via 2a03:2880:f373:1:face:b00c:0:25de → 301https://www.facebook.com/ via 2a03:2880:f373:1:face:b00c:0:25de → 200
works
 Load fb.com over IPv6 from up to six other places — a second opinion.

What's keeping fb.com from an A

  1. Mail servers without IPv6
    mxa-00082601.gslb.pphosted.com, mx0a-00082601.pphosted.com, mx0b-00082601.pphosted.com, mxb-00082601.gslb.pphosted.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

fb.com  Has IPv6

A (IPv4)57.145.2.1
AAAA (IPv6)2a03:2880:f373:1:face:b00c:0:25de

www.fb.com  Has IPv6

Alias ofwww.facebook.com → star-mini.c10r.facebook.com
A (IPv4)57.144.230.1
AAAA (IPv6)2a03:2880:f381:1:face:b00c:0:25de

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/vuuxGTP4fp · How we measure

Checked 2026-10-31 11:13:49 UTC. Full DNS report: dns.pizza/domain/fb.com · JSON: /api/v1/fb.com