FLoC Tracking Tech of Google Explained: Pros and Cons

FLoC Tracking Tech of Google Explained: Pros and Cons

Federated Learning of Cohorts or FLoC is a web tracking technology developed by Google based on the principles of artificial intelligence and machine learning, specifically federated learning. The tech giant began testing this tracker technology in its Google Chrome browser in March 2021 as part of its attempt to displace third-party cookies.

Explaining FLoC Web Tracking Technology: What It Is? How Does It Work?

FLoC is fundamentally a web tracking technology that aims to replace third-party cookies. Note that within the digital ads industry, advertisers deposit third-party cookies in the devices of web users to track their online activities and deliver targeted online ads. This practice has been receiving criticism and scrutiny because it has raised privacy concerns.

So how is tracking using FLoC different from cookies? The operating principle of FLoC is straightforward: it groups people into cohorts based on their browsing history to deliver interest-based advertising using federated learning. Note that federated learning is a machine learning technique that uses multiple servers to train algorithms instead of centralized servers.

Google Chrome serves as a tool for looking at the browsing history of its users and assigning them in different cohorts. It fundamentally profiles a particular individual based on his or her site visits. Once profiled and assigned to a specific cohort, it is up to a particular website or an ad server to determine what advertisements would appeal to him or her.

An example would be an individual who always browses pet-related websites. Chrome will analyze the browsing history of this person and patterns in his or her online behavior before assigning him or her to a specific cohort. This cohort might have been grouped for delivering ads related to pet food and supplements and grooming services, among others.

The tech giant claims that it would be able to deliver targeted ads without letting advertisers know the identity of web users. Google Chrome only processes the browsing history of each user for the purpose of assigning him or her into a cohort. The data remains private and will never be shared. FLoC has been positioned as a more private alternative to cookies.

Pros: Advantages of FLoC Tracking Technology

FLoC remains in the testing phase. However, Google is optimistic that this technology would finally replace the utilization and dependence on third-party cookies. It also believed that its web tracking technology is a solution to addressing the privacy issues that have emerged from the surveillance-heavy activities of the online advertising industry.

Below are the advantages of this web tracking technology from Google:

• Purported better privacy protection of web users: FLoC does not collect all sorts of data from a user to get a better picture of his or her identity and interest that could be used by advertisers for individual targeting. It simply profiles this user to assign him or her to a particular cohort. Advertisers target the cohort instead.

• Browser does the profiling and not third-party trackers: Cookies from third parties usually do the data collection and analysis of users. However, through FLoC, it tasks the browser to do the tracking and assigning users to suitable cohorts. The collected data from analyzed browsing history remains private.

• Interest-based advertising without third-party cookies: Another advantage of FLoC is that delivery of targeted ads based on individual audience interests is still possible even without using tracking cookies. The pool of cohorts that Google will build and expand serves as a guide for advertisers to target a specific audience.

Cons: Disadvantages of FLoC Tracking Technology

Technology undeniably resolves the privacy risks associated with third-party cookies. However, privacy experts have noted that it would create newer ones, as well as a range of problems. The fact remains that it is still a tool for delivering targeted advertising. Most critics of the online advertising industry and advocates of Internet anonymity have been vocal about their apprehension against the surveillance-reliant operation of advertisers.

Below are the disadvantages of this web tracking technology from Google:

• There are still privacy concerns and possible issues: Some of the privacy issues identified by critics include the possibility of painting a clearer picture of a specific user using the cohorts in which he or she belongs, grouping people by characteristics they wish to keep private such as sexuality and health, and possible point of entry for fingerprinting a device that can expose the identity of a user.

• Refusal of other browser developers to adopt and implement: Other browsers have refused to utilize the proposed tracking technology. This is another critical disadvantage of FLoC. Although Google Chrome remains the most popular web browser in the world, it might be impossible to establish the new web tracking solution of Google as a new standard, especially if other major players in the industry refuse its adoption.

• Presents a pressing disadvantage to Google Chrome browser: The privacy concerns over FLoC means that Google Chrome will suffer from the same criticism on top of its own privacy issues. Furthermore, because it is fundamentally an extension, it might add to the already resource-intensive requirement of the browser.

• Might put smaller ad tech companies at a disadvantage: Larger ad networks and ad technology companies might gain another competitive advantage through FLoC. Their capabilities could mean easier utilization of this new tracking technology from Google. However, smaller competitors do not have these capabilities.

• Demonstrates an attempt of Google to control the web: Other critics have explained that solutions like FLoC represent an attempt of a large company to control the web and ad industry. Government regulators have expressed concern over the ongoing efforts of Google to come up with solutions to replace third-party cookies. They noted that these solutions could create antitrust and anti-competition issues.


  • Bohn, D. 2021. “Privacy and Ads in Google Are About to Become Flocing Complicated.” The Verge. Available online
  • Cyphers, B. 2021. “Google’s FLoC is a Terrible Idea,” Electronic Frontier Foundation. Electronic Frontier Foundation. Available online
  • The Economist. 2021. “Why is FLoC, Google’s New Ad technology, Taking Flak?” The Economist. Available online