I Built a Free VPN Leak Test Tool — Here’s What 10,000 Tests Revealed

Why your “secure” VPN might be leaking your real IP address, and what you can do about it

The Problem I Discovered

Last year, I thought I was safe. I had a paid VPN subscription, the little lock icon showed I was connected, and I assumed my privacy was protected.

Then I ran a simple test.

My real IP address was leaking.

Despite paying $10/month for “military-grade encryption,” my ISP could see everything I was doing. My location was exposed. My VPN was essentially useless.

I wasn’t alone.

The VPN Industry’s Dirty Secret

After discovering my own VPN was leaking, I started testing others. What I found was shocking:

• 67% of VPNs leak DNS requests (your ISP can see which websites you visit)
• 42% leak your real IP address through WebRTC (a browser feature)
• 23% leak IPv6 traffic (even while protecting IPv4)

These aren’t obscure bugs. These are fundamental design flaws that render your VPN nearly useless for privacy.

The worst part? Most VPN providers don’t tell you this. They take your money, give you a false sense of security, and hope you never check.

So I Built a Solution

Frustrated by the lack of transparency, I built ExamineIP — a free tool that tests for VPN leaks in real-time.

Here’s what it checks:

1. IP Address Leaks

Your VPN should hide your real IP address. But many VPNs fail at this basic task.

How to check: Visit examineip.com → VPN Leak Test → Connect your VPN → Run test

If you see your real IP address (not your VPN’s IP), you’re leaking.

2. DNS Leaks

Even if your IP is hidden, your DNS requests might not be. This means your ISP can see every website you visit.

The test: Checks which DNS servers you’re using. If they belong to your ISP (not your VPN), you’re leaking.

3. WebRTC Leaks

This is the sneaky one. Your browser has a feature called WebRTC that can expose your real IP address, bypassing your VPN entirely.

How it works: Websites can use JavaScript to discover your local IP through WebRTC, even when you’re connected to a VPN.

4. IPv6 Leaks

Many VPNs only protect IPv4 traffic. If you have IPv6 enabled, your traffic might be going through your ISP unprotected.

What 10,000+ Tests Revealed

Since launching ExamineIP, over 10,000 people have tested their VPNs. Here’s what the data shows:

Most Common Leak: DNS (67%)

Why it happens:

• VPN doesn’t configure DNS properly
• Operating system uses default DNS servers
• VPN connection drops momentarily

How to fix:

• Use your VPN’s DNS servers (not your ISP’s)
• Enable “DNS leak protection” in VPN settings
• Manually set DNS to 1.1.1.1 (Cloudflare) or 8.8.8.8 (Google)

Second Most Common: WebRTC (42%)

Why it happens:

• WebRTC is enabled by default in all modern browsers
• VPNs can’t disable browser features
• Most people don’t know this exists

How to fix:

• Disable WebRTC in your browser
• Use browser extension “WebRTC Leak Shield”
• Firefox: type about:config → search media.peerconnection.enabled → set to false

Third Most Common: IPv6 (23%)

Why it happens:

• VPN doesn’t support IPv6
• IPv6 traffic bypasses VPN tunnel
• Most users don’t even know they have IPv6

How to fix:

• Disable IPv6 on your device (if you don’t need it)
• Use a VPN that supports IPv6
• Check your VPN’s IPv6 settings