Yes — catandpaste.app has IPv6.

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

IPv6 readiness

Website, mail and DNS all work over IPv6.

Website over IPv6 catandpaste.app has 4 IPv6 addresses and answers on every one we tested. ✓ 2001:4860:4802:38::15 answers · 443✓ 2001:4860:4802:32::15 answers · 443✓ 2001:4860:4802:36::15 answers · 443✓ 2001:4860:4802:34::15 answers · 443	yes
www over IPv6 www.catandpaste.app has 2 IPv6 addresses and answers on every one we tested. ✓ 2606:4700:3031::ac43:dfb6 answers · 443✓ 2606:4700:3036::6815:5093 answers · 443	yes
Mail servers (MX) have IPv6 Every mail server has an AAAA record. route3.mx.cloudflare.net ✓route2.mx.cloudflare.net ✓route1.mx.cloudflare.net ✓	yes
Nameservers have IPv6 2 of 2 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up. keaton.ns.cloudflare.com ✓vida.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://catandpaste.app/ via 2001:4860:4802:38::15 → 307https://catandpaste.app/en via 2001:4860:4802:38::15 → 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/catandpaste.app.svg)](https://aaaa.bot/catandpaste.app)

Check again

catandpaste.app Has IPv6

A (IPv4)	216.239.36.21 216.239.38.21 216.239.34.21 216.239.32.21
AAAA (IPv6)	2001:4860:4802:38::15 2001:4860:4802:32::15 2001:4860:4802:36::15 2001:4860:4802:34::15

www.catandpaste.app Has IPv6

A (IPv4)	172.67.223.182 104.21.80.147
AAAA (IPv6)	2606:4700:3031::ac43:dfb6 2606:4700:3036::6815:5093

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: catandpaste.app
Measured 2026-11-14 04:18:24 UTC by aaaa.bot (one server on Fly.io, region iad)

A (IPv4):    216.239.36.21, 216.239.38.21, 216.239.34.21, 216.239.32.21
AAAA (IPv6): 2001:4860:4802:38::15, 2001:4860:4802:32::15, 2001:4860:4802:36::15, 2001:4860:4802:34::15
www AAAA:    2606:4700:3031::ac43:dfb6, 2606:4700:3036::6815:5093

Readiness grade A: Website, mail and DNS all work over IPv6.
- Website over IPv6: catandpaste.app has 4 IPv6 addresses and answers on every one we tested.
    2001:4860:4802:38::15: answers (TCP 443)
    2001:4860:4802:32::15: answers (TCP 443)
    2001:4860:4802:36::15: answers (TCP 443)
    2001:4860:4802:34::15: answers (TCP 443)
- www over IPv6: www.catandpaste.app has 2 IPv6 addresses and answers on every one we tested.
    2606:4700:3031::ac43:dfb6: answers (TCP 443)
    2606:4700:3036::6815:5093: answers (TCP 443)
- Mail servers (MX) have IPv6: Every mail server 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://catandpaste.app/ via 2001:4860:4802:38::15 -> HTTP 307, certificate: valid
    https://catandpaste.app/en via 2001:4860:4802:38::15 -> HTTP 200, certificate: valid
DNS answers via DNS-over-HTTPS (Cloudflare). Method: https://aaaa.bot/method
Permanent link: https://aaaa.bot/r/mgwIDNH06B

Permanent link: aaaa.bot/r/mgwIDNH06B · How we measure

Checked 2026-11-14 04:18:24 UTC. Full DNS report: dns.pizza/domain/catandpaste.app · Age, certificate and blocklists: how.is/catandpaste.app · JSON: /api/v1/catandpaste.app