A DNS leak happens when your PC sends website lookups outside your VPN, revealing the sites you visit to your internet provider. To fix it on Windows 10, turn on your VPN app’s DNS leak protection and kill switch, make sure the VPN handles IPv6 (or turn IPv6 off on your adapter if it doesn’t), and stop Windows sending queries to every adapter by enabling Turn off smart multi-homed name resolution in Group Policy. Then run a DNS leak test again. Windows 10 reached end of support on October 14, 2025. Consumer Extended Security Updates (ESU) now run until October 12, 2027.
Quick Answer
Connect to the VPN and run a DNS leak test. If your provider’s servers show, turn on the VPN’s leak protection, handle IPv6, and enable Turn off smart multi-homed name resolution.
Step 1: Test for a Leak
- Connect to your VPN.
- Visit a DNS leak test site and run the extended test.
- If any listed DNS server belongs to your home internet provider rather than the VPN, you have a leak.
Step 2: Use the VPN’s Protection
- In the VPN app’s settings, turn on DNS leak protection (or “use VPN DNS only”).
- Turn on the kill switch so traffic stops if the VPN drops.
- Update the VPN app to the latest version.
Step 3: Stop Windows Querying Every Adapter
- Press Windows + R, type gpedit.msc (Pro and above) and press Enter.
- Go to Computer Configuration > Administrative Templates > Network > DNS Client.
- Double-click Turn off smart multi-homed name resolution, choose Enabled, and click OK.
- Restart, reconnect the VPN and test again.
Common Causes and Fixes
| Cause | Fix |
|---|---|
| VPN doesn’t force its DNS | Turn on DNS leak protection |
| IPv6 not covered by the VPN | Use a VPN with IPv6 support, or turn IPv6 off on the adapter |
| Windows queries all adapters | Enable the multi-homed policy |
| Browser uses its own secure DNS | Check the browser’s secure DNS setting matches your privacy goals |
| VPN connection drops | Turn on the kill switch |
Troubleshooting
- No Group Policy Editor: Windows 10 Home lacks gpedit.msc; rely on the VPN app’s protection.
- Still leaking: Flush the DNS cache. See clearing the DNS cache and checking DNS settings.
- Using Windows’ built-in VPN? See using the Windows VPN.
Frequently Asked Questions
Is a DNS leak dangerous?
It reveals the sites you look up to whoever runs that DNS server, usually your internet provider. It doesn’t expose passwords.
Should I change my DNS to a public server?
That changes who sees your lookups but doesn’t stop a leak while on a VPN. Fix the VPN’s DNS handling.
Does a leak test prove I’m private?
It checks DNS only. WebRTC leaks and browser tracking are separate.
Summary
- Run a DNS leak test with the VPN on.
- Turn on the VPN’s leak protection and kill switch.
- Handle IPv6 and enable the multi-homed policy.
- Test again.
Kermit Matthews is a freelance writer based in Philadelphia, Pennsylvania with more than a decade of experience writing technology guides. He has a Bachelor’s and Master’s degree in Computer Science and has spent much of his professional career in IT management.
He specializes in writing content about iPhones, Android devices, Microsoft Office, and many other popular applications and devices.