VPN Leak Test

Check if your VPN is leaking your real IP address, DNS requests, or WebRTC data. Free instant privacy test with no logs.

Check if your VPN is leaking your real IP, DNS requests, or WebRTC data

APIPOST /api/v1/network/vpn-leak/dns
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Key Features

100% Free

No registration required, unlimited checks

Instant Results

Real-time analysis with detailed output

REST API Access

Integrate into your workflow via API

Accurate Data

Live queries to authoritative sources

What is VPN Leak Test?

The VPN Leak Test checks whether your VPN connection is truly protecting your privacy by running three independent security checks. The IP Leak Test detects your public IPv4 and IPv6 addresses and verifies whether they belong to a VPN provider or your real ISP. The DNS Leak Test queries eight major public DNS resolvers (Cloudflare, Google, Quad9, OpenDNS, AdGuard, CleanBrowsing) to determine which DNS servers your browser is actually using — if your DNS requests bypass the VPN tunnel and go to your ISP's resolver, your browsing activity is exposed even though your IP appears masked.

The WebRTC Leak Test uses the browser's RTCPeerConnection API to check whether STUN server requests reveal your real public IP address — a common vulnerability that affects Chrome, Firefox, and Edge even with an active VPN. All tests run entirely in your browser and on our servers with no data stored or logged. Use this tool before trusting sensitive browsing to a VPN connection, after switching VPN servers or protocols, and to verify that your VPN provider actually delivers the privacy they promise.

How to Use

  1. 1Open the tool — all three tests (IP, DNS, WebRTC) start running automatically
  2. 2Review the IP Leak check: verify that your IPv4 address belongs to the VPN, not your ISP
  3. 3Check the DNS Leak results: all resolvers should be in the same country as your VPN server
  4. 4Inspect the WebRTC Leak test: no public IP addresses should differ from your VPN IP
  5. 5Look at the overall verdict badge: green means no leaks detected, amber or red indicates issues
  6. 6If leaks are found, disconnect VPN, fix the issue, reconnect, and re-run the test

Who Uses This

System Administrators

Monitor and troubleshoot infrastructure

Developers

Debug network issues and integrate via API

SEO Specialists

Verify domain configuration and performance

Security Analysts

Audit and assess network security

Frequently Asked Questions

What is a VPN leak and why is it dangerous?
A VPN leak occurs when data that should be encrypted and routed through the VPN tunnel instead travels over your regular internet connection, exposing your real IP address, DNS queries, or location to websites, ISPs, and network observers. This defeats the entire purpose of using a VPN. DNS leaks are the most common type — your browser sends domain name lookups to your ISP's DNS servers instead of the VPN's, revealing every website you visit. WebRTC leaks exploit browser APIs to discover your real IP even through a VPN. IP leaks happen when IPv6 traffic bypasses the VPN tunnel entirely.
How does the DNS leak test work?
The test queries a special diagnostic hostname through eight major public DNS resolvers (Google 8.8.8.8, Cloudflare 1.1.1.1, Quad9 9.9.9.9, OpenDNS, AdGuard, CleanBrowsing). Each resolver returns its own public IP address, which we then geolocate to determine the country and organization. If all resolvers show locations consistent with your VPN server country, there is no DNS leak. If any resolver shows your real country or ISP, your DNS requests are bypassing the VPN tunnel — a clear privacy leak.
What is a WebRTC leak and how do I fix it?
WebRTC (Web Real-Time Communication) is a browser feature used for video calls and peer-to-peer connections. It requires discovering your IP addresses via STUN servers, and this process can bypass VPN tunnels, revealing your real public IP to any website that runs a simple JavaScript snippet. To fix WebRTC leaks: in Firefox, set media.peerconnection.enabled to false in about:config. In Chrome, install a WebRTC-blocking extension like WebRTC Leak Prevent. Some VPN browser extensions also block WebRTC automatically. After making changes, re-run this test to verify the fix worked.
My VPN is connected but the test shows my real IP — what's wrong?
Several things can cause this: your VPN may have disconnected without notifying you (check the VPN app status), the VPN's kill switch may not be active (enable it in settings), IPv6 traffic may be bypassing the tunnel (disable IPv6 in your OS network settings or enable IPv6 leak protection in the VPN app), or your VPN protocol may not be routing all traffic (switch from split tunneling to full tunnel mode). Reconnect to the VPN and re-run this test. If the problem persists, try a different VPN server or protocol.
How often should I run a VPN leak test?
Run the test after every VPN connection or server switch, after OS or browser updates (which can reset network settings), after installing new browser extensions (some can cause WebRTC leaks), when switching between Wi-Fi and mobile data, and periodically as a routine check. Many VPN leaks are intermittent — they may not occur on every connection but appear randomly, especially during reconnections or network changes. Regular testing is the only way to catch these issues.

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API Endpoint

POST /api/v1/network/vpn-leak/dns
View Documentation