What Is a DNS Leak? How To Test For and Prevent DNS Leaks

A Domain Name System (DNS) leak can expose your IP address. An unprotected IP address means all your online activities can be tracked (such as the websites you visit or ads you click on). It also leaves you vulnerable to hackers who are after your personal information.

If you suspect your VPN is leaking DNS info, we have a full breakdown of what might have caused it, how to detect and fix it, and other kinds of information leaks you should watch out for. If you’re concerned about your technical abilities, don’t sweat it.

We cover the basics to help you troubleshoot your DNS leak and offer recommendations for the best VPNs to prevent future leaks.

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• Ultra-secure, high-speed VPN complete with malware protection and automatic blocking of intrusive ads and third-party trackers
• Other benefits include a premium password manager, dark web monitoring, and access to IP-restricted content
• 3 plans to choose from for custom protection on up to 10 devices

What is a DNS leak?

DNS is essentially the address book of the internet. When you type in a website, like www.AllAboutCookies.org, the DNS server translates that website name into computer language. It reaches out to where the site is hosted and requests that the site be sent to your web page. Then the hosting entity verifies your IP address and sends the website to your browser.

If you’re using a VPN, that entire interaction should be encrypted and hidden in your VPN tunnel. A DNS leak is when your VPN fails to encrypt that information by either sharing it with a third-party server or sending the request outside the protected VPN tunnel. It’s then possible for someone else to see your IP address and track your activities.

What are the dangers of DNS leaks?

When your IP address is leaked, bad actors can get access to your online data. They may send you annoying things like spam, but they can also try to phish you for more lucrative credentials like your bank account.

Less extreme repercussions include allowing your internet service provider (ISP) to see your activity. If your ISP doesn’t want you to access certain sites, this could lead to internet throttling. Similarly, you won’t be able to access out-of-market content or stream from international regions because your real IP will be visible.

Types of VPN leaks

If your VPN is leaking DNS information, then it’s likely there’s another place where it’s failing too. If your VPN is not working properly, several types of leaks can happen.

What causes DNS leaks?

There are various reasons you could experience a DNS leak, and it depends on your specific VPN provider. But here are the most common causes.

Low-quality or free VPNs

Free or low-quality VPNs may not have secure or private DNS servers that can effectively deliver your request. We recommend you use a high-quality VPN with its own DNS servers, such as NordVPN.

Manually configured VPNs

Unless you know what you’re doing, you may have accidentally misconfigured your VPN. If it’s getting blocked, you can learn how to bypass VPN blocks without compromising your security.

Manually configured DNS

You or someone providing support for your device may have reconfigured your DNS settings, which can interfere with your VPN’s ability to mask it. Make sure to talk with verified tech support from a trustworthy source to correct it.

Unauthorized third parties or apps

Some third-party apps or software may be altering your DNS settings, which would cause it to leak when paired with a VPN. Someone could also have poisoned your DNS cache so that it returns incorrect responses to your requests.

Lack of IPv6 support

IPv6 is newer than IPv4, and some VPNs may not be able to handle it properly. If your network connection is using IPv6, it’s likely to cause an IP address leak, but DNS leaks are also possible. If you can, or with the help of tech support, switch to IPv4.

Transparent DNS proxies

When you use a VPN’s DNS servers, the ISP may implement a transparent proxy so your traffic returns to your ISP. The only real solution is a quality VPN to circumvent the ISP.

Windows SMHNR

If you’re running Windows 8 or newer, Smart Multi-Homed Name Resolution (SMHNR) may overwrite your DNS settings if it thinks there’s a better server available. From our research, the only way to avoid this is to disable the feature.

How do I know if I have a DNS leak?

There are some telltale signs of DNS leaks. If a website isn’t what you expected or looks wrong, that could be one indication. Uncommonly slow internet speeds can also be a sign, but bear in mind speeds are influenced by several factors.

You may also see inconsistent location information. For example, you have a VPN server set to Germany, but your location is showing elsewhere. Of course, the easiest way to know if you have a DNS leak is to run a DNS leak test.

How to run a DNS leak test

1. Disconnect your VPN.
2. Visit the DNS Leak Test or Browser Leaks sites and write down the results (IP address is a good one to record).
3. Close out of the checker site completely.
4. Turn your VPN on.
5. Reopen your browser and navigate back to the test site.
6. If your information is the same as when your VPN was off, you have a leak.

How to prevent DNS leaks

There are plenty of reasons why DNS leaks occur and fixing them may not be simple. Below are some common troubleshooting techniques. Remember, you can reach out to your VPN’s tech support or an outside source like The Geek Squad for help too.

• Reset DNS settings. Simply restore everything to the recommended settings on your device.
• Reset VPN DNS settings. Reset your VPN settings to the recommended ones.
• Update OS. Check your device for operating system updates and implement all of them. Updates contain security patches and should always be implemented when they’re released.
• Change internet browsers. Your browser could be giving you trouble, so try switching to a different one.
• Connect to a different network. The problem could be connected to your ISP. Try connecting to a different network.
• Configure firewall settings to include DNS requests. Both soft and hard firewalls can be configured to include DNS requests. It’s important only to do this if you are completely comfortable with what you’re doing. Otherwise, reach out to verified support.
• Use a DNS proxy. This approach is a little more technical and involves manual configuration of the firewall or other proxy tools. We advise limiting this approach to users with technical experience.
• Use a different VPN. If you’re using a lower-quality VPN, it may be time to upgrade. Higher-quality VPNs have better DNS protection and tech support.

Best VPNs to prevent DNS leaks

If you’re looking for a new VPN, we’ve tested them all. These are some of the best VPNs available to keep your DNS secure.

• NordVPN offers support for IPv6 and includes built-in leak protection. For even more protection, you can count on NordVPN for private DNS servers.
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  5.0

  AllAboutCookies writers and editors score products based on a number of objective features as well as our expert editorial assessment. Our partners do not influence how we rate products.

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  On NordVPN's website

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  NordVPN

  Up to 72% off 2-year plans + a Saily eSIM data gift

  • Ultra-secure, high-speed VPN complete with malware protection and automatic blocking of intrusive ads and third-party trackers
  • Other benefits include a premium password manager, dark web monitoring, and access to IP-restricted content
  • 3 plans to choose from for custom protection on up to 10 devices

  Get NordVPN | Read NordVPN Review

• Surfshark VPN is another excellent choice that offers custom DNS servers and built-in leak protection. It also includes a Smart DNS proxy to make sure you have quality security.
  Unlimited Device Protection and Large Server Network

  

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  Surfshark

  7 day free trial on 12 and 24 month plans

  • All-in-one VPN app with 24/7 protection thanks to 3,200+ RAM-only servers in over 100 countries
  • Real-time malware defense, webcam protection, alternative ID creation, ad blocking, and more
  • One subscription covers unlimited devices for your entire household with access to 24/7 support

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• CyberGhost allows you to configure your DNS settings manually. It also contains built-in DNS and IPv6 leak protection and a Smart DNS proxy alongside the VPN.
  Leading Protection, Even on Smart TVs and Gaming Consoles

  

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  • High-speed global servers offering industry-leading 256-bit AES encryption and no data logs
  • Unlimited bandwidth, DNS and IP leak protection, and automatic kill switch available for up to 7 devices
  • Configurable with your router, smart TV, Amazon Fire TV stick, or gaming console
  • No split tunneling feature on desktop

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FAQs

Bottom Line

DNS leaks, a breach in the information shared during internet requests, pose potential security issues for VPN users. Some common reasons leaks occur include using a subpar VPN service, misconfigured VPNs and DNSs, unauthorized third parties or apps to name a few.

The best way to arm yourself against DNS leaks is to use one of the most secure VPNs available. You should also do regular checks of your system to make sure other issues aren’t causing leaks. Safeguarding your privacy leads to less spam and scams and even reduces your chances of identity theft.

Customizable Coverage That is Simple to Use

5.0

AllAboutCookies writers and editors score products based on a number of objective features as well as our expert editorial assessment. Our partners do not influence how we rate products.

Editorial Rating

Learn More

On NordVPN's website

VPN

NordVPN

Up to 72% off 2-year plans + a Saily eSIM data gift

• Ultra-secure, high-speed VPN complete with malware protection and automatic blocking of intrusive ads and third-party trackers
• Other benefits include a premium password manager, dark web monitoring, and access to IP-restricted content
• 3 plans to choose from for custom protection on up to 10 devices

Author Details

Mary James

About the Author

Mary is a seasoned cybersecurity writer with over seven years of experience. With a B.S. in Liberal Arts from Clarion University and an M.F.A. in Creative Writing from Point Park University, she educates audiences on scams, antivirus software, and more. Her passion lies in educating audiences on helpful ways to protect their data.