Google experimented with Federated Learning of Cohorts (FLoC). And it’s over now. FLoC is set to be replaced by “Topics.” So, let's take a look at how Topics tracks users. Google will be using Topics API to track your browsing habits in Chrome.

Negative feedback for FLoC

FLoC was introduced in 2021 in a developer origin trial in Chrome.

The Federated Learning of Cohorts, also known as FLoC, is a method used by advertisers to track user data in Chrome. Cohorts are a group of subjects that share a defining characteristic. So, although FLoC didn’t use cookies it was trying to identify and classify the user. It turns out this data was more useful to a demographer than a marketer. 

Advertisers can see the browsing habits of the cohorts without seeing in-depth information about those individuals. Each browsing individual got an anonymous ID. With this data, advertisers were supposed to send you personalized ads.

Reviews on FLoC were mixed. And Google decided it had to go. 

They listed some of the problems.

• FLoC added too much fingerprinting data to the ecosystem
• Stakeholders wanted the API to provide more user transparency
• Stakeholders wanted the API to provide more user controls
• FLoC cohorts might be sensitive
• FLoC shouldn’t automatically include browsing activity from sites with ads on them (as FLoC did in its initial experiment)

“In short, they are trying to address the significant pushback and concerns that the industry has provided,” Yahoo Chief Business Officer Iván Markman commented on the switch to Topics.

“It is yet to be seen whether this next iteration is workable, given how high level and short-time-spanned it is. Google’s FLoC received negative policy and industry feedback, and there was concern that FLoC IDs could have been exploited for cross-site user tracking. With the release of Topics API, Google is providing a higher level of user obfuscation and localized browser storage vs. a centralized storage location.”

Why use the Topics API

The Topics API is a similar, but more abstract concept than FLoC. Chrome identifies a few of your top interests to represent your browsing habits every week. For example, these interests can be general things like business, travel, or exercise.

If a website has opted-in to participate then Chrome selects only three topics or interests to share with its ad partners. Advertisers use these “Topics” to decide which ads to send your way. If exercise is one of your interests, you will probably see some exercise ads.

Topics are only stored for three weeks. And then they are deleted. The process occurs on your device rather than on external servers. The topics are a Google-curated list of 300 interests. 

As mentioned, this only applies to websites that are participating with “Topics.” Websites that don’t use the Topics API won’t receive any of this information from the browser.

This is a much less targeted and more general version of FLoC. There is a comprehensive list of 300 topics that can be assigned to a user by Chrome. The good news is the list of topics does not include things like race, gender, or sexual orientation.

Google will allow the user to see the topics that have been associated with individual browsing habits. If some Topics don’t interest you as a consumer, you can remove them in Chrome. 

Is there a way to Opt-Out?

Google just kicked things off this month. The developer trials of the Topics API are underway. Websites will have to implement the API tool. And do their own individual testing. 

One of the things users liked about FLoC is that you could opt-out of it.

The short answer is other than disabling some Topics we don’t know if you can opt-out of its replacement. At the time of this writing on January 26, 2022, the exact details haven’t been released. And it is uncertain if the Topics API will be enabled by default. Expect more information to be released soon.