Using a VPN does not automatically guarantee privacy. DNS leaks, IP leaks, WebRTC leaks, and IPv6 leaks can all expose your identity and browsing activity even when a VPN shows as connected. These vulnerabilities are silent — there are no warnings, no error messages, and no visible changes in your VPN client when a leak occurs. The only way to verify your protection is to test it.
VPN leaks fall into three main categories. DNS leaks expose the websites you visit to your ISP by sending DNS queries outside the VPN tunnel — your ISP sees a complete record of your browsing activity in real time. IP leaks directly expose your real IP address to websites and services, revealing your location and identity. WebRTC leaks exploit a built-in browser feature to discover your real IP address through JavaScript, completely bypassing VPN encryption at the network level. All three can occur simultaneously and independently.
These tools are designed for anyone who relies on a VPN for privacy — remote workers connecting through public Wi-Fi, people in regions with restricted internet access, journalists and researchers handling sensitive information, and IT professionals testing network security configurations. Whether you're a casual VPN user checking your setup or a security professional auditing a corporate VPN deployment, each tool below provides instant, actionable results.
All tools on this site are free, browser-based, and require no sign-up or account. Each test runs automatically on page load and delivers instant results with clear pass/fail indicators. Test your VPN today — and every time you update your client, switch to a new server, or connect to a new network.
Why You Should Test Your VPN Regularly
VPN software updates can inadvertently break leak protection. When a provider pushes a new client version, DNS routing settings, kill switch behaviour, and WebRTC handling can all change without any notification to the user. A test that passed last week may fail today after an automatic update. Running a complete leak test after every major VPN update takes less than 30 seconds and confirms your protection is still intact.
Switching VPN servers frequently increases the risk of a temporary leak during the reconnection window. Every time you disconnect from one server and connect to another, there is a brief moment where your device may send traffic outside the VPN tunnel. Users who switch servers frequently to access different geographic content should test after each server change to confirm the new connection is fully protected — especially if their VPN's kill switch is disabled.
Not all VPN providers are equal when it comes to leak protection. Budget and free VPN services frequently have poor or non-existent DNS leak protection, no IPv6 handling, and no WebRTC leak prevention. Independent studies have found that over 80% of free mobile VPN apps have some form of data leak. If you are using a free or budget VPN, running all three leak tests is essential to determine whether your traffic is actually protected or whether the VPN is providing a false sense of security.
Network environment changes are one of the most common triggers for VPN leaks. Connecting to a new Wi-Fi network, switching from Wi-Fi to mobile data, entering or leaving a corporate network, or resuming a device from sleep can all cause a VPN to briefly reconnect without full leak protection. A kill switch prevents traffic during these gaps, but not all VPNs include one — and on many VPNs that do, the kill switch is disabled by default and must be manually enabled.
NordVPN consistently ranks highest in independent leak protection tests, with built-in DNS, IPv6, and WebRTC leak prevention active on every server by default. Their protection has been independently audited by PricewaterhouseCoopers and Deloitte. ExpressVPN and Surfshark also perform well, with private DNS on every server and kill switch features. The key features to look for are: automatic kill switch, proprietary DNS servers, IPv6 leak blocking, and WebRTC protection at the network level.
Not sure if your DNS is leaking? Find out in seconds.