VPN tests: How to tell if a VPN is working


A virtual private network (VPN) helps encrypt your online activity, disguising your browsing. But what happens when a VPN fails you? That’s where a VPN test comes in.

VPN leaks occur when your real IP address becomes visible, even though a VPN is intended to mask your true IP address. Luckily, there are ways to determine if your VPN has a leak. Keep reading to learn how to conduct VPN tests  and verify their effectiveness. 

How do VPN leaks occur? 

vpn leak occurs

VPN leaks occur most often in one of three ways: 

1. WebRTC leaks

WebRTC leaks occur when your true IP address is leaked and exposed through your browser’s WebRTC functionality. What’s that? WebRTC is a basic technology feature that assists with peer-to-peer functionalities on your browser without the need to install plugins or other apps. 

2. DNS leaks

“DNS” stands for domain name system. It’s the system by which website names are translated into the long IP addresses that identify specific websites. In a DNS leak, your true IP address becomes exposed when your  DNS request is either sent unencrypted outside of your VPN or when your VPN server is somehow bypassed. 

3. Browser extension leaks

Something called “prefetching” is a browser function that makes searches quicker and more efficient, but it can come at the cost of reduced online privacy and data security if your VPN is leaking. Browser extension VPN leaks happen when Chrome VPN extensions “prefetch” a domain name by predicting what websites you are going to visit to speed up connections.

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How to conduct a VPN test (WebRTC VPN leaks)

WebRTC uses Session Traversal Utilities for NAT protocol — also known as STUN protocol. This enables your public IP address to make peer connections that expose your public IP address even if you are using a VPN. 

What is the first step to solving the problem? Find out whether you have the problem. This is why it’s important to test your VPN for IP address leaks. Follow the steps below to determine if you have a leak:·        

  • Step 1: Go to Google or another web browser and type in “what is my IP address.” Before you do this, make sure you’re not connected to your VPN. Write down your IP address.
  • Step 2: Log in to your VPN and verify that you are connected to the server of your choice.
  • Step 3: Go back to your browser and type in “what is my IP Address” and check your IP address again. It should show the masked IP address of your VPN.
  • Step 4: Finally, use one of several free websites to run a WebRTC VPN security test to check your VPN for  leaks.

If both steps 3 and 4 do not show your public IP address, you should be fine. But if your search shows your VPN- masked address — but the WebRTC test shows your public IP address — you have a leak.  

If you have a leak, you should disable WebRTC on your browser. This is done differently for each browser, either by changing settings or installing a plugin to do it. It’s worth noting that some VPNs will help protect against WebRTC  leaks. 

How to conduct a VPN test (DNS VPN leaks)

Sometimes when you are using a VPN, a DNS leak can occur. This happens when your DNS queries are sent outside of the secure VPN encrypted tunnel and your data is sent through your default DNS servers rather than the secure, anonymous VPN server. Often, a DNS VPN leak is due to improper configuration of your network settings. 

Unlike testing for a WebRTC leak, the best way to check for a DNS leak is to use a website. There are several free websites that you can use to test for a DNS leak, such as DNSleak.com*.  

If you find that you’re dealing with a DNS leak, there are several fixes you can try. Visit DNSleaktest.com* to find the best solution for your situation. 

How to test for browser extension VPN leaks

Browser extension VPN leaks occur due to prefetching. Prefetching is activated by default when using Chrome browsers. 

Here are steps you can take to test whether you have a browser extension VPN leak:        

  • Step 1: Activate the Chrome plugin on your VPN.
  • Step 2: Go to chrome://net-internals/#dns and click on “clear host cache.”
  • Step 3: Then go to any website to confirm the leak.

And if you find that there is a leak, you can use the following steps to help fix the issue:

  • Step 1: Go to Chrome://settings in your address bar.
  • Step 2: Go to “Search settings” and type in “predict.”
  • Step 3: Then disable the options “Use a prediction service to help complete searches and URLs typed in the address bar” and “Use a prediction service to load pages more quickly.”

Using things like public Wi-Fi while you shop or conduct personal banking or other financial transactions could put you at risk of having your data accessed and your identity compromised.

A VPN can help you avoid these dangers. Just do a VPN check first to make sure it doesn’t leak. 

VPN testing FAQs

Here are a few more frequently asked questions — and answers — about VPN tests. 

What is VPN testing?

VPN testing ensures that a user’s VPN connection is valid and continues to protect the private data stored and produced on IoT devices

Who should get a VPN?

Anyone interested in protecting their identity and IP address should consider protecting their devices with a VPN.  

When should I turn off VPN?

You should avoid turning off your VPN while you’re connected to the internet.  

Do I need a VPN on my phone?

Yes, it’s recommended that you protect all internet-enabled devices with a VPN. 

Can a VPN be hacked?

VPNs can be hacked, but it’s difficult to do so. Regardless, it’s much easier to be hacked without a VPN than with one.  

Can my ISP block my VPN?

Yes, an internet service provider (ISP) can block VPNs by blocking the IP address produced by the VPN to protect your device(s). 

Can a firewall block a VPN?

Yes, it’s possible for a smart firewall to block the IP address produced by your VPN.  

The freedom to connect more securely to Wi-Fi anywhere

With Norton™ Secure VPN, check email, interact on social media and pay bills using public Wi-Fi without worrying about cybercriminals stealing your private information

Try Norton Secure VPN for peace of mind when you connect online

Clare Stouffer
  • Clare Stouffer
  • Gen employee
Clare Stouffer, a Gen employee, is a writer and editor for the company’s blogs. She covers various topics in cybersecurity.

Editorial note: Our articles provide educational information for you. Our offerings may not cover or protect against every type of crime, fraud, or threat we write about. Our goal is to increase awareness about Cyber Safety. Please review complete Terms during enrollment or setup. Remember that no one can prevent all identity theft or cybercrime, and that LifeLock does not monitor all transactions at all businesses. The Norton and LifeLock brands are part of Gen Digital Inc. 


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