A VPN is indeed an amazing service to protect your privacy online, hide sensitive information from eavesdroppers and reach restricted content online. It has been a top choice to avoid being tracked by ISPs or governments, but is VPN an ad blocker as well and does it really protect you from being tracked by advertisers all across the internet?
All a VPN service does it creates a secure encrypted tunnel from your device to a VPN server, and from VPN server traffic reaches the destination website. That means that a connection is made to a website, but the website does not really know who you are, however, using a VPN your identity is masked only to a certain extent. Advertisers found different ways to identify you besides your IP address and a basic VPN as a technology on its own does not really block or protect you from online ads and still allow advertisers to identify you, so let’s explore how advertisers track you in the first place.
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How do ads follow you online
You have probably noticed at one point that as soon as you search something online the ads start tracing you everywhere you go. Data hoarding companies nowadays use sophisticated techniques to identify you online and sell your data to advertisers and that is happening even in real-time. New ways to identify the internet users online are emerging, but these three by far are the most popular methods advertisers use for tracking:
Browser and device fingerprinting
A cookie is a small file that stays on your browser and contains a user ID, session ID and other bits of text. It helps websites to function properly and allows a user to stay signed in or keep a shopping cart details after coming back to the website. Cookies have a unique property: they are domain bound, meaning that they only can be read by the website they belong to.
A tracking pixel is another popular technology to track users online.It is a really small one-pixel size dot that could be inserted into a website’s or email’s HTML code and usually made invisible to a person. This little tracking pixel contains a code which can be triggered as soon as a person visits the website or does a particular action online. The actions that are taken on the website determines the user behavior and helps to track conversions. The tracking pixel gives a user the unique identifier by which it can be tracked by reading a cookie on your device and sending information about you to a server. This pixel can gather information about your location, OS, browser, and activities on the website.
Speaking about browsers, there’s another ad tracking technique called browser fingerprinting.
This technique is used to identify or partially identify the internet user’s device and browser. When you visit a website the browser sends a lot of information about itself – for example, is it Mozilla or Chrome, what resolution does the screen has, what kind of plugins are installed, preferred language and OS information. While it seems that this information is very generic and any browser or device can have the same specifications, but the key is that the combination of these parameters allows identifying (or at least partially identify) an internet user and follow him online.
Does VPN block ads
VPN technology establishes a secure connection to the website and protects from outsiders snooping on your personal data, however since the connection is established to a website it still means that cookies from a website are stored on your device and generic browser information is sent. Having this in mind, the conclusion is that VPN technology on its own does not block ads and only has limited protection from ad tracking. But what about a VPN provider that says it can protect you from being tracked by those ads? Well, for a VPN service to block ads and protect you from being tracked by advertisers they need to implement additional features within their VPN app or whole VPN server infrastructure, and indeed a few VPN providers have those features that block adware, tracking and annoying ads while using their service.
How do VPNs block ads
VPN services block ads via blocking or redirecting DNS requests that are sent to advertising network servers. Since VPN providers usually use their own DNS servers it is relatively easy for them to control which websites and queries can be reached and which ones can not.
To block those tracking cookies and adware VPN providers must have a huge and continuously renewed lists of malicious domain names and IP addresses, and there are third-party services that provide those lists for a price.
The ads can be blocked by redirecting their advertiser networks IP addresses to an address that can not be resolved, for example, localhost or 0.0.0.0, this way the default browser window will be shown that the website is not reachable. Such redirects can happen on app or browser add-on level meaning that these queries are blocked at your device or a better solution that VPN providers use is to implement this technology on the server level, meaning that malicious traffic is redirected or blocked on the VPN server. This ad-blocking feature implementation on the whole VPN provider’s infrastructure ensures that this technology works on any VPN server, all devices including mobile and any OS.
Which VPNs block ads
While it is relatively not that hard to block such ads, however not that many VPN providers offer this feature of ad-blocking. Here are few VPN providers that are worth mentioning and they all use this server-side ad blocking technology:
PureVPN has a built-in ad-blocking feature (Update! While being cheap and reliable service, PureVPN does not offer this ad-blocking feature anymore as of December 2019)
CyberWaters is a mixed crew of cyber security enthusiasts with a keen interested in data privacy, security and technology behind it. We provide cyber security related content and give advise on best practices and tools how to stay safe and secure online.