Google’s brief experiment with Federated Learning of Cohorts (FLoC) has come to an end. The replacement is simply named “Topics.” Let’s take a look at how Google will use this to track your browsing habits in Chrome.
What Was FLoC?
Before we dive into “Topics,” let’s talk about what they’re replacing. Federated Learning of Cohorts (FLoC) was a method for advertisers to track user data in Chrome without cookies.
FLoC enables “behavioral targeting” without cookies. When you visit a website in Chrome, your browser history is assigned an identifier that puts you in a group with other people who have similar browsing history. These groups were called “cohorts.”
Advertisers could see the browsing habits of people in the cohort without seeing information about the individuals. Each person was given an anonymous ID. So the general idea was advertisers could serve you personalized ads without knowing your identity.
That’s a very brief explanation of FLoC. Our full explanation of how FLoC worked goes into more detail.
What Is “Topics”?
Topics is a similar idea to FLoC, but it’s a little more abstract. Chrome identifies a few of your top interests to represent your browsing habits each week. For example, these interests can be general things like “sports” or “travel.”
Then, when you visit a participating website, Chrome selects three interests to share with its advertising partners. Advertisers use these “Topics” to decide which targeted ads to serve you. If “sports” is one of your interests, you’ll probably see some sports ads, etc.
Topics are stored for three weeks and then deleted. The selection process happens on your device, not on any external servers. The topics that Chrome associates with your browsing history come from a list of 300 that Google has curated. That list doesn’t include things like gender or race.
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.
How Is Topics Different Than FLoC?
The main difference between Topics and FLoC is there are no cohorts. While cohorts were designed to keep people anonymous, there were still methods that could be used to pinpoint users.
Cohorts were the main feature of FLoC. Chrome gathered data about you to assign you to a cohort, then that cohort was shared with the website advertisers to deliver targeted ads. Topics, on the other hand, only share interests with advertisers, which are not associated with specific users.
In general, think of Topics as a less-specific version of FLoC. We don’t know the full list of 300 topics that Chrome can assign to a user, but we know they don’t include things like gender, race, or sexual orientation.
Can I Opt-Out?
One of the good things about FLoC is you could opt-out of it. At the time of writing on January 25, 2022, we don’t have the exact details, but it looks like Google will allow Chrome users to disable Topics. We don’t know if it will be enabled by default.
Additionally, Google will allow you to see the topics that have been associated with your browsing habits. You can remove the topics that you don’t think fit, though there is no way to add your own topics—if that’s even something you’d want to do.
When Will “Topics” Roll Out?
Google will start things off with developer trials of the Topics API in Chrome. Before anyone can use it, websites will have to implement it and do their own testing. Google announced it in January 2022, and it will likely be a while before this is is widespread enough for it to impact a majority of your browsing.