VPN Leak Test

A Virtual Private Network (VPN) is designed to encrypt your internet traffic and mask your real IP address by routing your connection through a secure server. However, even the best VPN connections can sometimes leak information that compromises your privacy. These leaks can expose your true location, browsing habits, and identity to websites, advertisers, your Internet Service Provider (ISP), and potentially malicious actors.

VPN leaks occur when data that should travel through the encrypted VPN tunnel instead bypasses it, going directly over your regular internet connection. This can happen silently, meaning you might think you are protected when you are actually not. Running regular leak tests is the only way to confirm that your VPN is working as intended.

Types of VPN Leaks

1. WebRTC Leaks

WebRTC (Web Real-Time Communication) is a browser technology that enables peer-to-peer communication for video calls, voice chat, and file sharing. To establish direct connections between users, WebRTC uses STUN (Session Traversal Utilities for NAT) servers to discover your public and local IP addresses. The problem is that this IP discovery process can bypass your VPN tunnel entirely, revealing your real IP address to any website that runs a simple JavaScript snippet.

WebRTC leaks are particularly concerning because they work in all major browsers including Chrome, Firefox, Edge, and Opera. Even if your VPN is properly encrypting all other traffic, a WebRTC leak can expose your true IP address without any visible warning. Some VPN providers include built-in WebRTC leak protection, but you can also disable WebRTC manually in your browser settings or use browser extensions to block it.

2. DNS Leaks

Every time you visit a website, your device sends a DNS (Domain Name System) query to convert the domain name into an IP address. When connected to a VPN, these DNS queries should be routed through the VPN tunnel to your VPN provider's DNS servers. A DNS leak occurs when your DNS queries are instead sent to your ISP's DNS servers or other third-party resolvers outside the VPN tunnel.

DNS leaks are dangerous because they reveal every website you visit to your ISP, even though your actual browsing traffic is encrypted. This means your ISP can build a complete profile of your online activity. DNS leaks commonly happen when your operating system is configured to use specific DNS servers that override the VPN's DNS settings, when the VPN connection drops momentarily, or when using split tunneling configurations.

3. IPv6 Leaks

As the internet transitions from IPv4 to IPv6, many VPNs still only tunnel IPv4 traffic. If your ISP supports IPv6 and your VPN does not handle IPv6 traffic, your IPv6 requests will travel outside the VPN tunnel on your regular connection. This exposes your real IPv6 address and the associated geolocation data to every website you visit.

IPv6 leaks are increasingly common because more ISPs are rolling out IPv6 support while many VPN providers have been slow to add full IPv6 compatibility. The safest approach is to either use a VPN that fully supports IPv6 tunneling or disable IPv6 on your device entirely while connected to the VPN.

How to Fix VPN Leaks

• Enable kill switch: A VPN kill switch blocks all internet traffic if the VPN connection drops, preventing any data from leaking through your regular connection.
• Use VPN DNS servers: Configure your VPN to handle all DNS queries. Most premium VPNs like NordVPN run their own private DNS servers and route all queries through the encrypted tunnel.
• Disable WebRTC: In Firefox, navigate to about:config and set media.peerconnection.enabled to false. For Chrome, use an extension like WebRTC Leak Prevent.
• Disable IPv6: If your VPN does not support IPv6, disable it in your operating system's network settings to prevent IPv6 traffic from bypassing the tunnel.
• Use a reputable VPN: Free VPNs are notorious for leaks and poor security. Choose a paid VPN with a proven track record of independent audits and no-log policies.
• Keep software updated: VPN client updates often include fixes for newly discovered leak vulnerabilities. Always run the latest version.
• Test regularly: Network changes, OS updates, and VPN client updates can all introduce leaks. Run this test periodically to ensure your VPN is still protecting you.

Why VPN Leaks Matter

VPN leaks undermine the core purpose of using a VPN: privacy and anonymity. If your real IP address is leaking, websites can track your location, your ISP can monitor your browsing activity, and your data may be vulnerable on public Wi-Fi networks. For journalists, activists, and anyone in restrictive regions, a VPN leak can have serious consequences beyond just privacy concerns.

Even for everyday users, leaks mean that advertisers can build tracking profiles based on your real IP, streaming services can enforce geographic restrictions despite your VPN, and your ISP can throttle your connection based on the type of content you access. Regular leak testing is a simple but essential step in maintaining your online privacy.

How This Tool Works

Our VPN leak test runs entirely in your browser using client-side JavaScript. The WebRTC test creates a temporary peer connection using STUN servers to detect if your browser exposes any public IP addresses outside the VPN tunnel. The DNS test checks which IP address is visible to our server when you make a request, allowing you to compare it against your VPN provider's IP range. The IPv6 test attempts to connect via IPv6 to detect whether IPv6 traffic is being properly tunneled. No data is stored or logged from these tests.