DNS Leak Test
Check if your DNS queries are exposed to your ISP
Run a full speed test — includes download, upload, ping, and jitter measurements.
What this test measures
A DNS leak occurs when your device sends DNS queries through your ISP's DNS server even while connected to a VPN or using a custom DNS provider. This exposes your browsing activity to your ISP despite the VPN. A DNS leak test checks which DNS servers are actually handling your queries.
How to interpret your results
| Result | Rating | Typical context |
|---|---|---|
| No leak | Secure | Queries only go through your chosen DNS or VPN provider |
| ISP DNS leak | Risk | ISP can see every domain you visit despite VPN |
| Multiple resolvers | Partial | Some queries leak; check DNS settings on each device |
| WebRTC leak | Risk | Browser exposes real IP through WebRTC; disable in browser settings |
What affects your result
- VPN DNS configuration — A poorly configured VPN client sends DNS queries outside the VPN tunnel. Check your VPN app's DNS leak protection settings.
- Split tunneling — If split tunneling is enabled, apps excluded from the VPN also send DNS queries outside the tunnel — and those queries leak.
- IPv6 leaks — If your VPN only tunnels IPv4 but your device has IPv6, DNS queries via IPv6 bypass the VPN tunnel. Disable IPv6 on the VPN adapter or use a VPN that handles both protocols.
- Operating system DNS cache — Windows and macOS cache DNS results. Old cached entries from before VPN connection can resolve via the wrong server.
How to run an accurate test
Connect to your VPN (if testing VPN DNS isolation), then run the test. The result should show only your VPN provider's DNS servers, not your ISP's. If ISP DNS servers appear: your VPN has a DNS leak.
Frequently Asked Questions
How do I fix a DNS leak?
Enable 'DNS leak protection' in your VPN client settings. Switch to a VPN that forces all DNS through its own servers. Manually set DNS on your network adapter to your VPN provider's DNS servers. Disable IPv6 if your VPN does not support it.
Does changing DNS to 1.1.1.1 prevent DNS leaks?
Changing DNS to 1.1.1.1 prevents your ISP from logging your DNS queries when you are not using a VPN. It does not prevent DNS leaks through a VPN — that requires VPN-level DNS isolation.
What is a WebRTC leak?
WebRTC is a browser API used for video calls that can expose your real IP address even behind a VPN. Test with a WebRTC leak test tool and disable WebRTC in your browser (via an extension like uBlock Origin or browser settings) to prevent this.