What is a DNS leak?
A DNS leak occurs when your DNS requests are sent outside your VPN tunnel – typically to your ISP's DNS servers instead of your VPN provider's servers. Even though your internet traffic is encrypted by the VPN, your DNS queries reveal which websites you are visiting to your ISP.
This defeats one of the main purposes of using a VPN – keeping your browsing activity private from your ISP and network observers.
Without DNS leak (correct)
Your device→ VPN tunnel
DNS query→ VPN DNS server
Your ISP seesOnly VPN connection
PrivacyProtected
With DNS leak (problem)
Your device→ VPN tunnel
DNS query→ ISP DNS server (leak!)
Your ISP seesAll websites you visit
PrivacyCompromised
Common causes of DNS leaks
Windows Smart Multi-Homed DNSWindows sends DNS to all available servers
IPv6 DNS leakVPN only tunnels IPv4, IPv6 DNS leaks
Misconfigured VPNDNS not routed through VPN tunnel
WebRTCBypasses VPN tunnel entirely
Split tunnelingSome apps bypass the VPN
How to fix DNS leaks
Use DNS leak protectionEnable in your VPN client settings
Set manual DNS1.1.1.1 or 8.8.8.8
Use DNS-over-HTTPSEncrypts DNS queries in browser
Disable IPv6If VPN does not support IPv6
Choose a better VPNUse one with built-in DNS leak protection
DNS leaks – the hidden VPN vulnerability
A DNS leak is one of the most common VPN vulnerabilities. Even with a VPN active, DNS queries can bypass the encrypted tunnel and reach your ISP's DNS servers, revealing every website you visit. DNS leaks can occur due to Windows settings, misconfigured VPNs, IPv6 issues or WebRTC. Always test your VPN with a DNS leak test to ensure your privacy is truly protected.