Yes — office365online.com has IPv6.

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

Measured 2026-11-02 20:55 UTC. We reuse a result for up to a week, so we aren't testing the same site over and over. Check office365online.com now

IPv6 readiness

Works over IPv6, with gaps: one of its IPv6 addresses doesn't answer; www doesn't fully work over IPv6; its nameservers lack IPv6.

Website over IPv6 3 of 4 IPv6 addresses for office365online.com don't answer. Visitors sent to those wait for a timeout before falling back. ✗ 2a05:d014:179b:c400:2b16:26d0:c04c:4fef no answer✓ 2600:1f1c:6db:8801:9173:d91:a3b8:2148 answers · 443✗ 2600:1f1c:6db:8800:3874:4c01:cb9:391f no answer✗ 2600:1f1c:6db:8801:b190:5302:8b46:f792 no answer– 2600:1f1c:6db:8800:79cb:1ef5:7739:e6be not tested– 2406:da1e:214:c901:49:871:e9e1:eb92 not tested– 2600:1f1c:6db:8801:5056:7a82:ae7e:8cec not tested– 2600:1f1c:6db:8801:7620:4565:8dce:8b5a not tested	partly
www over IPv6 3 of 4 IPv6 addresses for www.office365online.com don't answer. Visitors sent to those wait for a timeout before falling back. ✗ 2a05:d014:179b:c400:2b16:26d0:c04c:4fef no answer✓ 2600:1f1c:6db:8801:9173:d91:a3b8:2148 answers · 443✗ 2600:1f1c:6db:8800:3874:4c01:cb9:391f no answer✗ 2600:1f1c:6db:8801:b190:5302:8b46:f792 no answer– 2600:1f1c:6db:8800:79cb:1ef5:7739:e6be not tested– 2406:da1e:214:c901:49:871:e9e1:eb92 not tested– 2600:1f1c:6db:8801:5056:7a82:ae7e:8cec not tested– 2600:1f1c:6db:8801:7620:4565:8dce:8b5a not tested	partly
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 No nameserver has an AAAA record — an IPv6-only resolver can't reach this domain's DNS. ns1.dns-redirect.com ✗ns2.dns-redirect.com ✗	no

First measured 2026-11-02; last confirmed 2026-11-02.

HTTPS over IPv6 · not part of the grade yet
office365online.com didn't complete an HTTPS request over IPv6 (timed out).

https://office365online.com/ via 2a05:d014:179b:c400:2b16:26d0:c04c:4fef · timed out

What's keeping office365online.com from an A

One of office365online.com's IPv6 addresses doesn't answer
2a05:d014:179b:c400:2b16:26d0:c04c:4fef, 2600:1f1c:6db:8800:3874:4c01:cb9:391f, 2600:1f1c:6db:8801:b190:5302:8b46:f792 didn't accept a connection on 443 or 80 while others did. Remove them from DNS or fix that server — browsers that pick one wait for a timeout.
One of www.office365online.com's IPv6 addresses doesn't answer
2a05:d014:179b:c400:2b16:26d0:c04c:4fef, 2600:1f1c:6db:8800:3874:4c01:cb9:391f, 2600:1f1c:6db:8801:b190:5302:8b46:f792 didn't accept a connection on 443 or 80 while others did. Remove them from DNS or fix that server — browsers that pick one wait for a timeout.
Nameservers without IPv6
ns1.dns-redirect.com, ns2.dns-redirect.com 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

office365online.com Has IPv6

A (IPv4)	195.201.128.179 5.161.47.86 76.223.91.20 46.62.237.138 5.78.156.59 5.161.230.87
AAAA (IPv6)	2a05:d014:179b:c400:2b16:26d0:c04c:4fef 2600:1f1c:6db:8801:9173:d91:a3b8:2148 2600:1f1c:6db:8800:3874:4c01:cb9:391f 2600:1f1c:6db:8801:b190:5302:8b46:f792 2600:1f1c:6db:8800:79cb:1ef5:7739:e6be 2406:da1e:214:c901:49:871:e9e1:eb92 2600:1f1c:6db:8801:5056:7a82:ae7e:8cec 2600:1f1c:6db:8801:7620:4565:8dce:8b5a

www.office365online.com Has IPv6

A (IPv4)	195.201.128.179 5.161.47.86 76.223.91.20 46.62.237.138 5.78.156.59 5.161.230.87
AAAA (IPv6)	2a05:d014:179b:c400:2b16:26d0:c04c:4fef 2600:1f1c:6db:8801:9173:d91:a3b8:2148 2600:1f1c:6db:8800:3874:4c01:cb9:391f 2600:1f1c:6db:8801:b190:5302:8b46:f792 2600:1f1c:6db:8800:79cb:1ef5:7739:e6be 2406:da1e:214:c901:49:871:e9e1:eb92 2600:1f1c:6db:8801:5056:7a82:ae7e:8cec 2600:1f1c:6db:8801:7620:4565:8dce:8b5a

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

IPv6 measurement: office365online.com
Measured 2026-11-02 20:54:54 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    195.201.128.179, 5.161.47.86, 76.223.91.20, 46.62.237.138, 5.78.156.59, 5.161.230.87
AAAA (IPv6): 2a05:d014:179b:c400:2b16:26d0:c04c:4fef, 2600:1f1c:6db:8801:9173:d91:a3b8:2148, 2600:1f1c:6db:8800:3874:4c01:cb9:391f, 2600:1f1c:6db:8801:b190:5302:8b46:f792, 2600:1f1c:6db:8800:79cb:1ef5:7739:e6be, 2406:da1e:214:c901:49:871:e9e1:eb92, 2600:1f1c:6db:8801:5056:7a82:ae7e:8cec, 2600:1f1c:6db:8801:7620:4565:8dce:8b5a
www AAAA:    2a05:d014:179b:c400:2b16:26d0:c04c:4fef, 2600:1f1c:6db:8801:9173:d91:a3b8:2148, 2600:1f1c:6db:8800:3874:4c01:cb9:391f, 2600:1f1c:6db:8801:b190:5302:8b46:f792, 2600:1f1c:6db:8800:79cb:1ef5:7739:e6be, 2406:da1e:214:c901:49:871:e9e1:eb92, 2600:1f1c:6db:8801:5056:7a82:ae7e:8cec, 2600:1f1c:6db:8801:7620:4565:8dce:8b5a

Readiness grade C: Works over IPv6, with gaps: one of its IPv6 addresses doesn't answer; www doesn't fully work over IPv6; its nameservers lack IPv6.
- Website over IPv6: 3 of 4 IPv6 addresses for office365online.com don't answer. Visitors sent to those wait for a timeout before falling back.
    2a05:d014:179b:c400:2b16:26d0:c04c:4fef: no answer
    2600:1f1c:6db:8801:9173:d91:a3b8:2148: answers (TCP 443)
    2600:1f1c:6db:8800:3874:4c01:cb9:391f: no answer
    2600:1f1c:6db:8801:b190:5302:8b46:f792: no answer
    2600:1f1c:6db:8800:79cb:1ef5:7739:e6be: not tested
    2406:da1e:214:c901:49:871:e9e1:eb92: not tested
    2600:1f1c:6db:8801:5056:7a82:ae7e:8cec: not tested
    2600:1f1c:6db:8801:7620:4565:8dce:8b5a: not tested
- www over IPv6: 3 of 4 IPv6 addresses for www.office365online.com don't answer. Visitors sent to those wait for a timeout before falling back.
    2a05:d014:179b:c400:2b16:26d0:c04c:4fef: no answer
    2600:1f1c:6db:8801:9173:d91:a3b8:2148: answers (TCP 443)
    2600:1f1c:6db:8800:3874:4c01:cb9:391f: no answer
    2600:1f1c:6db:8801:b190:5302:8b46:f792: no answer
    2600:1f1c:6db:8800:79cb:1ef5:7739:e6be: not tested
    2406:da1e:214:c901:49:871:e9e1:eb92: not tested
    2600:1f1c:6db:8801:5056:7a82:ae7e:8cec: not tested
    2600:1f1c:6db:8801:7620:4565:8dce:8b5a: not tested
- Mail servers (MX) have IPv6: No MX records, so mail goes to the domain's own address (implicit MX). It 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).

HTTPS over IPv6 (not graded): office365online.com didn't complete an HTTPS request over IPv6 (timed out).
    https://office365online.com/ via 2a05:d014:179b:c400:2b16:26d0:c04c:4fef (timed out)
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/U4NUfz9862

Permanent link: aaaa.bot/r/U4NUfz9862 · How we measure

Checked 2026-11-02 20:54:54 UTC. Full DNS report: dns.pizza/domain/office365online.com · Age, certificate and blocklists: how.is/office365online.com · JSON: /api/v1/office365online.com