Yes — threadfastai.dev has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 threadfastai.dev has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3035::6815:3fda answers · 443✓ 2606:4700:3030::ac43:ac0d answers · 443	yes
www over IPv6 www.threadfastai.dev has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3035::6815:3fda answers · 443✓ 2606:4700:3030::ac43:ac0d 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. leif.ns.cloudflare.com ✓nancy.ns.cloudflare.com ✓	yes

HTTPS over IPv6 · not part of the grade yet
Loads over IPv6 with a valid certificate after 1 redirect: HTTP 200.

https://threadfastai.dev/ via 2606:4700:3035::6815:3fda → 302https://bold-pine-7a23.cloudflareaccess.com/cdn-cgi/access/login/threadfastai.dev?kid=88f47034843b4fe67fa6ece1bb4c1d4fc71848580b20e2dff53dd9e1c984733d&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6ImY0ZjY0NDcwZjVjOThiM2QzNGY2NWUwMjJiYzdjYTQzOThkZmNlYzZlNTVmOTRmMGMyNWNlMTM0MGViODg1ZTEifQ.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.H7IMd7uND0W2cKFkWbIOO9006l7TQRZAeV_VQBzNUG14AG9r41vC2IXjhnmLKOl3fHfcQzD4IKgkpWTnF_HzP3ETXlYGxHsQ4Gy1__3dPbZWV92xDYG_XdjRZ30vp00bP2Rm8XzDZTwpE4QTFtXXfGGqtNdWA3pljeHvfuL5JwQX3myra2UJoSOtwUfkeVdMKYSTw8CgETDyu9i6g02KeywGdqmLaUxEDoDyXdZiBSQr-hX6F76L1ZPc3h3D4cHqVs9Dp22cBrUg0h72hJwgO38MBu85ab0nkj76DE1coLUWr8adzS05-ufPSqEJnBDjRxya-e-5qMm_HajGmKtc7g&redirect_url=%2F via 2606:4700:300a::6813:c31d → 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/threadfastai.dev.svg)](https://aaaa.bot/threadfastai.dev)

Check again

threadfastai.dev Has IPv6

A (IPv4)	104.21.63.218 172.67.172.13
AAAA (IPv6)	2606:4700:3035::6815:3fda 2606:4700:3030::ac43:ac0d

www.threadfastai.dev Has IPv6

A (IPv4)	104.21.63.218 172.67.172.13
AAAA (IPv6)	2606:4700:3035::6815:3fda 2606:4700:3030::ac43:ac0d

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: threadfastai.dev
Measured 2026-11-08 16:23:11 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    104.21.63.218, 172.67.172.13
AAAA (IPv6): 2606:4700:3035::6815:3fda, 2606:4700:3030::ac43:ac0d
www AAAA:    2606:4700:3035::6815:3fda, 2606:4700:3030::ac43:ac0d

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: threadfastai.dev has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3035::6815:3fda: answers (TCP 443)
    2606:4700:3030::ac43:ac0d: answers (TCP 443)
- www over IPv6: www.threadfastai.dev has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3035::6815:3fda: answers (TCP 443)
    2606:4700:3030::ac43:ac0d: answers (TCP 443)
- 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: 2 of 2 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 after 1 redirect: HTTP 200.
    https://threadfastai.dev/ via 2606:4700:3035::6815:3fda -> HTTP 302, certificate: valid
    https://bold-pine-7a23.cloudflareaccess.com/cdn-cgi/access/login/threadfastai.dev?kid=88f47034843b4fe67fa6ece1bb4c1d4fc71848580b20e2dff53dd9e1c984733d&meta=eyJ0eXAiOiJKV1QiLCJhbGciOiJSUzI1NiIsImtpZCI6ImY0ZjY0NDcwZjVjOThiM2QzNGY2NWUwMjJiYzdjYTQzOThkZmNlYzZlNTVmOTRmMGMyNWNlMTM0MGViODg1ZTEifQ.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.H7IMd7uND0W2cKFkWbIOO9006l7TQRZAeV_VQBzNUG14AG9r41vC2IXjhnmLKOl3fHfcQzD4IKgkpWTnF_HzP3ETXlYGxHsQ4Gy1__3dPbZWV92xDYG_XdjRZ30vp00bP2Rm8XzDZTwpE4QTFtXXfGGqtNdWA3pljeHvfuL5JwQX3myra2UJoSOtwUfkeVdMKYSTw8CgETDyu9i6g02KeywGdqmLaUxEDoDyXdZiBSQr-hX6F76L1ZPc3h3D4cHqVs9Dp22cBrUg0h72hJwgO38MBu85ab0nkj76DE1coLUWr8adzS05-ufPSqEJnBDjRxya-e-5qMm_HajGmKtc7g&redirect_url=%2F via 2606:4700:300a::6813:c31d -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/Tk6fQXfwK0

Permanent link: aaaa.bot/r/Tk6fQXfwK0 · How we measure

Checked 2026-11-08 16:23:11 UTC. Full DNS report: dns.pizza/domain/threadfastai.dev · Age, certificate and blocklists: how.is/threadfastai.dev · JSON: /api/v1/threadfastai.dev