▓▒░ /ipv6-leak-test ░▒▓

IPv6 Leak Test

Find out if IPv6 traffic is escaping your VPN tunnel and exposing your real address.

★ isvpnworking.com - Live Status Window
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⚡ live status check ⚡
checking . . .
running 3 tests on your connection, hold tight
FYI we're checking your IP, location, and 3 types of leaks. all in your browser, nothing sent to us.
visible IP →
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they think you're in →
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VPN brand detected →
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tested at →
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┌─ LEAK DETECTION RESULTS ─┐
▸ webrtc test peer-to-peer ip leak
running…
▸ dns test domain query leak
running…
▸ ipv6 test protocol exposure
running…
★ TOP PICKS ★

VPNs that actually don't leak.

tested by us · using our own tool · we're picky
#1 BEST
NordVPN
$3.39/mo
our paranoid friend uses this one
click me ↗
#2 CHEAP
Surfshark
$2.49/mo
unlimited devices, decent speed
click me ↗
#3 ANON
Mullvad
$5/mo
accepts cash. literal envelopes.
click me ↗
★ The IPv6 leak: a 30-year-old protocol's revenge
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Quick version: many VPN clients only tunnel IPv4 and pretend IPv6 doesn't exist. If your ISP supports IPv6 (most do now), websites with IPv6 endpoints see your real IPv6 - even when your IPv4 traffic is safely tunneled.

Why this exists at all

IPv6 was designed in the 1990s to replace IPv4 because the world ran out of IPv4 addresses. Adoption was slow until cellular carriers and large ISPs started rolling it out aggressively in the 2010s. Today, around 45% of US Google traffic is IPv6, and that share keeps climbing.

The problem: VPN protocols (OpenVPN, WireGuard, IKEv2) all support IPv6, but a lot of VPN providers' apps don't actually configure IPv6 routes on the system. So your IPv4 traffic goes through the tunnel, but your IPv6 traffic uses the default ISP route - leaking your real IPv6 to every website that supports it.

How the leak shows up

Open Google. Google has both IPv4 and IPv6 endpoints. Your browser will prefer IPv6 if available (this is called "Happy Eyeballs"). Without proper VPN handling, Google logs your real IPv6 address while your VPN provider thinks it's tunneling everything. You appear "in the VPN country" to IPv4-only sites and "in your real country" to IPv6-aware sites.

Streaming services in particular check both. Netflix, BBC iPlayer, and Disney+ all use IPv6. If your IPv6 leaks, geo-restriction fails - you'll get the "you appear to be using a VPN" message even though IPv4 looks clean.

Three ways to fix an IPv6 leak

1. Use a VPN that handles IPv6 properly

The cleanest fix. Pick a VPN that explicitly states what it does with IPv6:

  • Tunnels IPv6: Mullvad, ProtonVPN, AirVPN. Best choice if you want IPv6 working through the VPN.
  • Blocks IPv6 entirely: NordVPN, Surfshark, ExpressVPN. Slightly less elegant but works - IPv6 traffic just dies, falling back to IPv4 (which is tunneled).
  • Ignores IPv6: a long tail of free and small VPN providers. Avoid.

2. Disable IPv6 at the OS level

Works as a stopgap, breaks slowly over time as more services go IPv6-only. Steps:

  • Windows 10/11: Settings -> Network -> change adapter options -> right-click Wi-Fi/Ethernet -> Properties -> uncheck "Internet Protocol Version 6 (TCP/IPv6)"
  • macOS: System Settings -> Network -> Wi-Fi -> Details -> TCP/IP -> Configure IPv6 -> Link-local only (or Off via terminal: networksetup -setv6off Wi-Fi)
  • Linux: add net.ipv6.conf.all.disable_ipv6=1 to /etc/sysctl.conf and reboot

3. Block IPv6 at the router

If you control your router, disabling IPv6 at the router level catches every device on the network. Most consumer routers have a toggle under Advanced Settings -> IPv6. The downside is everyone in your house loses IPv6 - usually harmless, occasionally annoying.

Reading our IPv6 row

The "ipv6 test" badge has three states:

  • SAFE - api64 returned an IPv4 address. Either your system has no IPv6, your VPN is blocking IPv6, or your VPN is tunneling IPv6 to a non-leaky address.
  • EXPOSED - api64 returned an IPv6 address. Your browser is reaching the internet over IPv6, which usually bypasses VPN tunnels. If you have a VPN on, this is a leak.
  • N/A - the request failed (network blocked, browser denied, ad-blocker stripped). Treat as inconclusive.

Bottom line

IPv6 leaks were the dirty secret of the VPN industry for years - then streaming geo-checks started using IPv6, the leak got embarrassing, and most reputable providers fixed it. The free and budget tier still hasn't. Run this test, and if it shows EXPOSED, switch providers or disable IPv6 at the OS level until you do.

FAQ
Why is IPv6 a leak risk if my VPN works on IPv4? [+]

Many VPN providers only route IPv4 traffic through the tunnel and let IPv6 traffic escape via your ISP. So websites that support IPv6 (most of Google, Facebook, Cloudflare-hosted sites) see your real IPv6 address while you imagine your VPN is hiding you. The ISP also sees those IPv6 connections in plaintext.

How does our IPv6 test know if I'm leaking? [+]

We hit api64.ipify.org from your browser - that endpoint returns whichever IP version your connection used. If it returns an IPv6 address, your browser is reaching the public internet over IPv6 (and probably outside your VPN tunnel). If it returns IPv4 or fails entirely, IPv6 isn't a leak source for you right now.

Should I just disable IPv6 entirely? [+]

It's a working solution. On Windows: Network and Sharing Center -> adapter properties -> uncheck IPv6. On macOS: Network -> Advanced -> TCP/IP -> Configure IPv6 -> Off. On Linux: add 'net.ipv6.conf.all.disable_ipv6=1' to sysctl.conf. The downside: some apps assume IPv6 is available and break in subtle ways. Better fix: use a VPN with IPv6 support (NordVPN, Mullvad, ProtonVPN) so IPv6 traffic also goes through the tunnel.

What if my VPN provider says they 'block IPv6'? [+]

Most do. NordVPN, Surfshark, ExpressVPN explicitly drop IPv6 traffic at the firewall when connected, so IPv6 leak risk drops to zero. The downside is IPv6-only services break, but that's vanishingly rare in 2026. Mullvad and ProtonVPN actually tunnel IPv6 - both safer and more compatible.

I'm on cellular data and the test shows IPv6 - is that a problem? [+]

Most US/EU cellular networks now do IPv6 by default. If you're not using a VPN, an IPv6 result is just normal. If your VPN is on and the test shows IPv6 with a non-VPN address, your VPN client isn't blocking IPv6 - either re-enable kill switch / IPv6 leak protection in settings, or pick a different provider.