Google has killed off FLoC, introduces Topics for ad tracking instead

Back in 2021, Google announced Federated Learning of Cohorts (FLoC), an initiative under its Privacy Sandbox proposal, where your data could be sent to advertisers for personalized experiences in a privacy-preserving manner. The proposal faced backlash from Vivaldi, Brave, WordPress, and Microsoft's GitHub, among many others, leading Google to delay its rollout in the same year. Today, the company has announced that it has officially killed off FLoC, and will instead be shifting focus to "Topics".

Through Topics, your web browser will determine your top interests for the week based on your browsing activity. These interests will be stored locally on your device for a period of three weeks - after which they will be deleted - and will not be sent to any external server, even those belonging to Google. When you visit a website, only three topics belonging to you will be shared with the website and its ad partners. This will comprise of one topic from each week and no more.

Google has emphasized that it is building controls in Chrome for users to remove certain topics or disable the capability completely. The company also noted that:

More importantly, topics are thoughtfully curated to exclude sensitive categories, such as gender or race. Because Topics is powered by the browser, it provides you with a more recognizable way to see and control how your data is shared, compared to tracking mechanisms like third-party cookies. And, by providing websites with your topics of interest, online businesses have an option that doesn’t involve covert tracking techniques, like browser fingerprinting, in order to continue serving relevant ads.

You can get an overview of the Topics API on Google's dedicated website here and view the in-progress technical implementation on GitHub here. A developer trial for Topics will be available in Chrome soon and future development on the API and its associated user controls will be based on that and upcoming feedback.