🌐 IPv6 Test
Check whether your connection supports IPv6, see your IPv6 and IPv4 addresses and detect dual-stack mismatches.
Click the button to test IPv4 and IPv6 connectivity at the same time.
💡 Why IPv6 matters for privacy
Many VPNs tunnel only IPv4. If your network also has IPv6 and the destination supports it, the browser can take a direct IPv6 route that bypasses the VPN and exposes your real address. The tell is simple: if IPv4 and IPv6 belong to different networks or providers, traffic is splitting across both stacks.
🔐 The test runs in your browser and only contacts public IP services (ipify.org). Nothing is sent to 0Appz.
How to use this tool
Overview
IPv6 Test checks IPv6 connectivity in your browser. Click once and the tool tests IPv6 and IPv4 at the same time, showing your addresses and classifying your connection as dual-stack, IPv4-only or IPv6-only. This matters for privacy: many VPNs tunnel only IPv4, so an active IPv6 stack can bypass the tunnel and expose your real address. If IPv4 and IPv6 belong to different networks, traffic is splitting across both stacks. The test only contacts public IP services (ipify.org). Nothing is uploaded to 0Appz.Why dual-stack matters for privacy
Most VPNs tunnel IPv4 only. If your device also has a working IPv6 address, browsers may prefer IPv6 for sites that support it, sending that traffic outside the tunnel and exposing your real address and ISP. The test resolves both stacks from your browser and classifies the connection: dual-stack (both available), IPv4-only (IPv6 absent or blocked) or IPv6-only. If the two addresses belong to different networks, traffic is splitting between providers, which is the classic setup for a silent leak.
Capabilities and constraints
| Property | IPv6 test behavior |
|---|---|
| Tests | IPv4 and IPv6 connectivity in parallel |
| Classifies | Dual-stack, IPv4-only or IPv6-only |
| Shows | Both addresses and their apparent networks/ISPs |
| Data source | Public IP service (ipify.org) |
| Stored by 0Appz | Nothing |
| Cost | Free, no account, unlimited tests |
Privacy: results stay in the page
The test contacts a public IP service from your browser, as any website would, and displays the result locally. 0Appz stores nothing about the addresses returned, and the page works offline after loading.
Acting on the result
- Dual-stack with one provider and a working VPN is the healthy case.
- Two different networks behind a VPN suggests IPv6 is bypassing the tunnel.
- Disabling IPv6 at the OS level is the quickest fix when the VPN lacks support.
- Choose VPN providers that tunnel IPv6 natively when available.
- Re-test after network changes; mobile carriers vary by region.
Related: browse the privacy and security tools for DNS and WebRTC leak checks.
IPv6 adoption, dual stack and what the test shows
IPv6 exists because the world ran out of IPv4 addresses, but adoption is uneven, which is why a connection can be IPv6-capable in one place and not in another. The test reports whether your current connection can reach IPv6-only hosts and what address the outside world sees. Three outcomes are common. Full dual stack means both protocols work and the network prefers IPv6 when available, which is the goal. IPv4-only means the ISP, the router or the device has not enabled IPv6; older routers and some VPNs are the usual cause. Partial connectivity, an IPv6 address but no working route, is the confusing case, and it can make some sites slow rather than unreachable, because the browser tries IPv6 first and waits for the timeout before falling back. That is why the test checks reachability, not just address presence. DNS matters too: a hostname only becomes reachable over IPv6 if it has an AAAA record, so a site can support IPv6 and still be reached over IPv4 by name. Carrier-grade NAT on mobile and many home connections hides many users behind one IPv4 address, which is another reason IPv6 matters. The test runs from your browser and stores nothing.
Frequently asked questions
What is an IPv6 test? +
An IPv6 Test checks whether your connection can reach the internet over IPv6 and shows your IPv6 and IPv4 addresses so you can see whether your network is dual-stack.
Why does my IPv6 show as not detected? +
Your ISP or router may not have IPv6 enabled, or your device may have it turned off. You can keep using IPv4 normally, without IPv6 there is nothing to leak.
What is a dual-stack network? +
Dual-stack means your connection runs IPv4 and IPv6 at the same time. Most modern networks are dual-stack.
Can IPv6 leak my real IP behind a VPN? +
Yes. Many VPNs tunnel only IPv4. If your network also has IPv6, traffic can take a direct IPv6 route outside the VPN and expose your real address. Compare the IPv6 you see here with your VPN provider network.
Does the test cost anything or require an account? +
Yes. It is 100% free with no sign-up. The test only contacts public IP services (ipify.org); 0Appz stores nothing.