DNS Leaks: What They Are & Why Your VPN Might Fail
The hidden privacy threat even good VPNs miss—and how to test for it.
By Australian VPN
What Is a DNS Leak?
DNS = Domain Name System. It's like the phonebook of the internet. When you type "google.com", DNS translates it into an IP address (142.250.185.46) so your browser knows where to go.
A DNS leak happens when: Your device accidentally sends DNS requests to your ISP's servers instead of through your VPN. Your ISP sees EVERY website you visit—even with VPN enabled.
Example: You're using a VPN but visit pornhub.com. Your ISP's DNS server logs the request with your real IP. Your VPN doesn't hide it.
How Serious Is It?
🚨 Very Serious
Your ISP can see your browsing history despite using a VPN. They could:
- Throttle your connection for certain sites
- Sell data to advertisers
- Report "suspicious" activity to authorities
- Block sites your ISP doesn't like
How To Test For DNS Leaks
- Disconnect from VPN (baseline test)
Turn off your VPN. Visit our DNS Leak Test tool at /tools/dns-leak-test.
- Note your ISP's DNS servers
The tool will show your ISP name (e.g., "Telstra") and their DNS servers (8.8.8.8, 1.1.1.1).
- Connect to your VPN
Choose a VPN server (any country) and establish connection.
- Run DNS test again
Refresh the DNS Leak Test. Check if DNS servers have changed.
- Compare results
If DNS shows your ISP's servers: LEAK DETECTED. If DNS shows VPN provider's servers: SAFE.
DNS Leak Results Explained
✓ SAFE: DNS matches VPN provider
Example: Shows "Cloudflare" or "NordVPN DNS" instead of Telstra. Your browsing is private.
❌ LEAKED: DNS shows your ISP
Example: Shows "Telstra DNS Servers" while VPN is connected. Your browsing visible to ISP.
⚠️ WARNING: Multiple DNS providers
Shows both Telstra AND Cloudflare. Some requests leak, some don't. Unreliable protection.
How To Fix DNS Leaks
✓ Fix #1: Choose a Better VPN
Premium VPNs (NordVPN, ExpressVPN, Surfshark) offer built-in DNS leak protection. Cheap/free VPNs often don't.
✓ Fix #2: Enable DNS Protection in VPN Settings
Most modern VPNs have a "DNS Protection" or "IPv6/DNS Leak Prevention" toggle. Turn it ON.
✓ Fix #3: Use VPN's Custom DNS
VPN apps let you set DNS manually. Use your VPN provider's DNS (not your ISP's). Example: NordVPN = 103.86.96.100
✓ Fix #4: Use System-Level DNS on Mac/Windows
Settings → Network → DNS → Set to VPN provider's DNS. Applies to all apps, not just browser.
Best VPNs for DNS Leak Protection
NordVPN
Built-in DNS/IPv6 leak protection. Rarely reports leaks. Strong track record.
ExpressVPN
Custom DNS infrastructure prevents leaks. 100% tested for zero leaks.
Surfshark
Advanced DNS protection. Cheapest option with strong leak protection.
Why This Matters to You
If your VPN leaks DNS:
- ISP sees every site you visit (no matter the VPN)
- Torrenting downloads are visible to your ISP
- Streaming services see your real location (can trigger blocks)
- Browsing habits can be sold to data brokers
Test Yours Now
Your VPN might be leaking. Use our free DNS Leak Test tool to find out in 30 seconds.