IPv6 Test
This page tests your own connection right now: your browser contacts a host that exists only on IPv6, and the result below tells you whether IPv6 works end to end. Looking for a different check? Test whether a website supports IPv6 instead.
| IPv6 connectivity | testing… |
| Your public IPv6 address | testing… |
| Address type | — |
How this test works
Your browser requests api6.ipify.org, a host published with an AAAA record and
no usable IPv4 path. Because the name can only be reached over IPv6, a successful response is
proof that every hop in the chain carries IPv6: your operating system has a routable address,
your router forwards IPv6, and your ISP routes it to the public internet. A failure means one
of those three links is missing — the test cannot tell you which one on its own, but the
troubleshooting order below narrows it down quickly.
The address shown is your public IPv6 address, the one servers see. Unlike IPv4, there is normally no NAT in front of it, so this is the actual address assigned to your device rather than a shared router address.
Reading your result
| IPv6 works | Your connection is IPv6-capable. Combined with an IPv4 address (which you almost certainly also have), you are dual-stack. |
| IPv6 not detected | The IPv6-only host could not be reached. Your connection is IPv4-only, or IPv6 is disabled somewhere on the path. Nothing is broken — see the fixes below. |
| Address starts with 2000–3fff | A normal global unicast address, routable on the public internet. |
| Address starts with fd or fc | A unique local address (ULA). It works inside your network but is not routable on the internet, so this is not real IPv6 connectivity. |
| Address starts with fe80 | A link-local address. It only works on the local segment and never leaves your router. |
What is dual-stack?
Most connections with working IPv6 are dual-stack: they hold an IPv4 and an IPv6 address at the same time. When you open a site, your device looks up both the A and AAAA records and races the two connections against each other — the Happy Eyeballs algorithm (RFC 8305) — preferring IPv6 but falling back to IPv4 within milliseconds if it stalls. This is why enabling IPv6 almost never breaks anything, and why you normally have no idea which protocol carried your last page load.
Why your ISP might not give you IPv6 yet
IPv4 has roughly 4.3 billion addresses and the regional registries handed out their last general-purpose blocks years ago. Rather than deploy IPv6, many providers chose the cheaper short-term route: put thousands of subscribers behind one shared public IPv4 address using carrier-grade NAT. That works for browsing but breaks inbound connections, which is why self-hosting, some peer-to-peer applications, and remote access often fail on those connections. IPv6 solves that permanently because every device can hold its own globally routable address. Background: why the world ran out of IPv4 addresses.
IPv6 not detected — how to fix it
- Check the router first. In its admin interface look for an IPv6 or "WAN IPv6" section. It usually needs to be set to obtain an address automatically (DHCPv6 or SLAAC) and to delegate a prefix to the LAN. A router that has IPv6 itself but does not delegate a prefix leaves every device behind it IPv4-only.
- Disconnect any VPN and retest. Many VPN clients disable IPv6 system-wide to prevent traffic escaping the tunnel. If IPv6 appears when the VPN is off, this is the cause — and it is intentional. Confirm with the WebRTC leak test.
- Check the operating system. IPv6 can be switched off per network adapter in Windows, macOS, and Linux, sometimes by an old troubleshooting guide or a security tool. Make sure it is enabled on the adapter you are actually using.
- Ask your ISP. If the router and OS are both fine, the provider is not routing IPv6 to you. Some enable it only on newer equipment or specific plans; asking for a modem or plan that supports it is often all that is required.
- Mobile is usually ahead. If IPv6 fails on home broadband, try the same test on a phone using mobile data. Many carriers run IPv6-only cores with NAT64 translation, so IPv6 frequently works there long before it works at home.
Testing IPv6 from the command line
curl -6 -s https://api6.ipify.org — forces IPv6 and prints your address.
ping6 ipv6.google.com — basic reachability, though some networks drop ICMP.
ip -6 addr show (Linux) or ipconfig (Windows) — shows whether your
adapter even has a global address starting with 2 or 3.
dig AAAA example.com +short — checks whether a site publishes an IPv6 address at
all. To check a whole domain properly, use the
website IPv6 test.
Frequently Asked Questions
How do I test if I have IPv6?
Open this page. Your browser is asked to load a resource from a host that only has an IPv6 address, so the request can only succeed if IPv6 works across your device, router, and ISP. If it succeeds you see your public IPv6 address; if it fails, some link in that chain is IPv4-only.
Do I need IPv6?
For everyday browsing, no. Every major site is still reachable over IPv4, and dual-stack devices fall back automatically. IPv6 matters if you want direct inbound connections (self-hosting, game servers, remote desktop) on a connection stuck behind carrier-grade NAT, or if you are on a mobile network that is already IPv6-only internally.
Why does my IPv6 address change so often?
By design. Most operating systems generate temporary IPv6 addresses that rotate every few hours to make long-term tracking harder, on top of a stable address used for incoming connections. Your ISP may also change the whole delegated prefix when the router reconnects.
Why does IPv6 stop working when I connect to a VPN?
Many VPN clients deliberately disable or block IPv6 on the device because their tunnel only carries IPv4. Without that, IPv6 traffic would bypass the tunnel entirely and expose your real address. Seeing IPv6 disappear while connected is usually the VPN doing its job.
My router says IPv6 is enabled but this test fails. Why?
The most common cause is that the router obtained an IPv6 address for itself but is not delegating a prefix to the LAN, so your devices never get a routable address. Other causes are an IPv6 firewall rule blocking outbound traffic, a VPN or security suite disabling IPv6, or an ISP that only enables IPv6 on newer equipment.
Sources
- RFC 8200 — Internet Protocol, Version 6 (IPv6) Specification
- RFC 4291 — IP Version 6 Addressing Architecture
- RFC 8305 — Happy Eyeballs Version 2
- RFC 8981 — Temporary Address Extensions for SLAAC
- APNIC — IPv4 exhaustion and address policy
Related tools
Check whether a specific website supports IPv6, check the other protocol with the IPv4 checker, learn the differences in our IPv4 vs IPv6 guide, or see both addresses at once on the main IP checker.