Yes — tailscale.com has IPv6.

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

This is a saved measurement from 2026-10-31 06:04 UTC. Check tailscale.com live now

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 tailscale.com has 2 IPv6 addresses and answers on every one we tested. ✓ 2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8 answers · 443✓ 2600:9000:a51d:27c1:6748:d035:a989:fb3c answers · 443	yes
www over IPv6 www.tailscale.com has 2 IPv6 addresses and answers on every one we tested. ✓ 2600:9000:a51d:27c1:6748:d035:a989:fb3c answers · 443✓ 2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8 answers · 443	yes
Mail servers (MX) have IPv6 Every mail server has an AAAA record. aspmx.l.google.com ✓alt3.aspmx.l.google.com ✓alt4.aspmx.l.google.com ✓alt1.aspmx.l.google.com ✓alt2.aspmx.l.google.com ✓	yes
Nameservers have IPv6 4 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. ns-1359.awsdns-41.org ✓ns-1558.awsdns-02.co.uk ✓ns-197.awsdns-24.com ✓ns-557.awsdns-05.net ✓	yes

HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate: HTTP 200.

https://tailscale.com/ via 2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8 → 200

works

Nothing keeping you from an A

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

Check again

tailscale.com Has IPv6

A (IPv4)	76.76.21.21
AAAA (IPv6)	2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8 2600:9000:a51d:27c1:6748:d035:a989:fb3c

www.tailscale.com Has IPv6

A (IPv4)	76.76.21.21
AAAA (IPv6)	2600:9000:a51d:27c1:6748:d035:a989:fb3c 2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8

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: tailscale.com
Measured 2026-10-31 06:04:33 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    76.76.21.21
AAAA (IPv6): 2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8, 2600:9000:a51d:27c1:6748:d035:a989:fb3c
www AAAA:    2600:9000:a51d:27c1:6748:d035:a989:fb3c, 2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: tailscale.com has 2 IPv6 addresses and answers on every one we tested.
    2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8: answers (TCP 443)
    2600:9000:a51d:27c1:6748:d035:a989:fb3c: answers (TCP 443)
- www over IPv6: www.tailscale.com has 2 IPv6 addresses and answers on every one we tested.
    2600:9000:a51d:27c1:6748:d035:a989:fb3c: answers (TCP 443)
    2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8: answers (TCP 443)
- Mail servers (MX) have IPv6: Every mail server has an AAAA record.
- Nameservers have IPv6: 4 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.

Reachability = a TCP connection opened on port 443 (or 80).

HTTPS over IPv6 (not graded): Loads over IPv6 with a valid certificate: HTTP 200.
    https://tailscale.com/ via 2600:9000:a602:b1e6:5b89:50a1:7cf7:67b8 -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/-bRfhHzzRw

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

Checked 2026-10-31 06:04:33 UTC. Full DNS report: dns.pizza/domain/tailscale.com · JSON: /api/v1/tailscale.com