Hacker working on his computer, Hacker stealing password and data from moblie phone , identity theft and computer crime concept.

When you surf the web, you must have seen various ads on Google search page results. Most of these might not interest you, but some may seem like they are targeted to you only.  Now, recall if you have searched for any product shown in the ad on your phone or PC. If you see the ad, you must have. The first question that might have hit your mind right now is,


How does that happen? How could someone know that this is your device?


The answer to these questions is cross-device tracking!


As per Statista, in the US, an average person has access to around 10 devices that are connected to the web. It is the reason cross-device tracking has become increasingly popular in the past few years, as it boosts sales for marketing companies. Let’s see how!

What is cross-device tracking?

Cross-device tracking is an online advertising practice that combines information from different devices of a single user. It allows marketers to deliver personalized online ads that are more useful and relevant.


For example, if a user is looking for a new smartphone online using their PC at home, marketers can reach the same user with mobile ads while they are commuting to work.


Cross-device tracking aims to target users based on what they do across multiple devices. The goal behind this is to show ads that are relevant and useful for the user. Google has stated that they want to provide users with more personalized content, leading ads to conversion.


You can see cross-device tracking in action by using any browser on your phone or PC, as well as visiting a website from your laptop and then observing the adverts you see later.

What are the various types of cross-device tracking?

Yes, it seems like a lucrative method. However, it is not that easy to implement. The success or failure of this method entirely depends on your approach. There are basically two types of cross-device tracking techniques that you can implement to get an insight into user behavior.

Deterministic tracking

The best way of cross-device tracking is by using an identifier, like a login credential. This method for cross-device targeting is the most accurate as no one has the same ID as you do. Firms like Facebook, Twitter, Instagram use this technique as they collect your login credentials once you sign up for their services.


The data collected about the user, in this case, is the most accurate, which is the reason users can be precisely targeted with ads. However, this method does not provide an overall view of the user’s online activity. The obtained insights will be limited to the company’s website.


Most ad-targeting campaigns use this cross-device tracking technique. The method actually includes scanning huge amounts of data using algorithms and devising insights about when and what type of devices the user interacts with. The algorithms segregate users based on locations, IP addresses, and similar behavior across devices.


This technique, as per its name, has no precise data but just patterns for ad targeting.

What are the various cross-device identifiers?

There are various identifiers that marketers use to track the users. Some of them are:


  • Device IDs such as Google advertising ID or IDFA for Apple
  • Registration data like login ID
  • Third-party cookies
  • Device fingerprinting
  • OS generated device

How can you evade tracking?

It is pretty obvious that if someone is tracked, they might not like it that much. Think of anyone knowing what you are doing on your device right now. If someone knows that you are reading this, they might not be able to track you as you will be implementing the following methods:

Use a VPN

The best way to keep yourself from tracking is by using a VPN. Why? A VPN software is a tool that encrypts every bit of information about your internet activities. It also stops IP-based tracking because it masks your IP address. Thus, you have the opportunity to no longer give away your approximate location. Typically, all websites and online services you visit can freely pinpoint your location. With a VPN, they will see the location you have selected when connecting to a VPN server.

Use a Privacy Browser

If you think incognito mode is secure, you might be mistaken. If you want to keep yourself from tracking, it is best to use a private browser like Brave, Tor, DuckDuckGo rather than the incognito mode in Google Chrome. These browsers do not profile you or save any of your personal data for sharing further with the marketers.

Change App Permissions

The apps on your smartphone may have some permissions that might not be required. For instance, why would Google Chrome need access to your microphone? If apps on your phone have such non-required permissions, you need to revoke these permissions.

Final Words

In today’s world, privacy is not what it used to be several years back. There are various tools and techniques that marketers use for tracking you and your online activity. If you don’t like being tracked, it is time to put in some effort. However, tracking can help you get what you need online faster.