Google stops FLoC and proposes Topics API as a cookie replacement

Google will definitively stop using the cookie alternative FloC. Instead, the company is proposing the new Topics API. That API should make tracking cookies superfluous. Chrome determines user interests on a weekly basis. Websites can tailor advertisements accordingly.

With Topics, Chrome uses an algorithm to determine the topics of interest for that week, while not connecting to servers, including Google’s, the search giant says. The topic list is saved in the browser for three weeks and then disappears. As a result, there is no history of topics available, claims Google.

The Topics API allows advertisers to tailor ads to user groups based on last week’s interests, which should therefore match what users want to see. For example, a form of targeted advertising must remain possible without tracking cookies, Google states.

To further guarantee the privacy of users, Google also sends a random topic along with the relevant topics for a user. This should prevent fingerprinting and ensure that a group is created that is large enough to achieve k-anonymity.

Topics replaces FLoC, Federated Learning or Cohorts. FLoC was an API that came under Google’s plans to eventually replace tracking cookies with locally generated data about surfing behavior. Users were then divided into cohorts based on that data. Advertisers could then have shown ads only to people who fall within certain cohorts, without knowing who exactly is in that cohort. FLoC was widely criticized: for example, it would give Google an even greater dominant position in the online advertising market and it would also not exclude fingerprinting based on data about cohorts.