DNS Leaks Explained — Privacy Guide
What are DNS leaks and why they matter for privacy. Learn how to prevent DNS leaks with VPN and test for vulnerabilities.
By the Australian VPN team · Reviewed by Josh (Brisbane)
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.
Every site visit starts with a DNS lookup — turning a name like netflix.com into an address. When a VPN is set up properly, those lookups travel inside the tunnel. A leak means your device quietly keeps asking your ISP's resolver instead, so the ISP still learns every site name you visit even though the traffic itself is encrypted.
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.
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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).
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Connect to your VPN
Choose a VPN server (any country) and establish connection.
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Run DNS test again
Refresh the DNS Leak Test. Check if DNS servers have changed.
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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)
- Your download activity is 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.
Related Reading
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View VPN Reviews →Australian VPN Team · Reviewed by Josh
Independent VPN reviews written for Australians, from Australia. We test from Brisbane on a standard NBN connection — see exactly how in our methodology — and every provider fact we publish is checked against the provider's own current pages. No provider pays for a ranking.
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