Google Topics replaces FLoC: What’s changed?

What is Google Topics?

Topics is Google’s new Privacy Sandbox proposal for interest-based advertising. It works by selecting three topics per user to inform relevant advertising  - one topic for each of the past three weeks. It calculates these topics from a user’s top 5 topics per week using browsing information local to the browser (plus one additional topic “chosen uniformly at random”). Advertisers will then be able to use these three topics to inform the advertising they serve. These could be things such as ‘sport’, ‘travel’ or ‘rock music’. The list proposed currently contains around 350 topics to reduce the risk of fingerprinting.

The topics selected are based solely on an individual device, without using external servers, and topics are deleted after three weeks. Google states: “Topics enables browsers to give you meaningful transparency and control over this data, and in Chrome, we’re building user controls that let you see the topics, remove any you don’t like or disable the feature completely.” 

How is it different to FLoC?

Unlike FLoC, Topics doesn’t involve the concept of cohorts of users who share common behaviours. Topics will also not make use of sensitive categories, with Google stating that Topics are “thoughtfully curated to exclude sensitive categories, such as gender or race”. Topics will also be deleted from a person’s history every three weeks. It adds that, after experimenting with FLoC last year, it “received valuable feedback from regulators, privacy advocates, developers and industry. The new Topics API proposal addresses the same general use case as FLoC, but takes a different approach intended to address the feedback received for FLoC. Chrome intends to experiment with the Topics API in 2022 and is no longer developing FLoC.” The move follows the CMA’s consultation at the end of 2021 into Google’s modified Privacy Sandbox commitments. 

Find a technical explainer with more detail on how Topics differ from FLoC here. 

What’s next? 

Google will soon be launching a developer trial of Topics in Chrome that includes user controls and enables website developers and the ads industry to try it out.

After more? 

• Read a blog post by Vinay Goel Product Director of Privacy Sandbox: Get to know the new Topics API for Privacy Sandbox
• Find a technical explainer on Topics here
• Find an overview, including a short video, here
• Find developer documentation here
• Sharing feedback directly via the public channels (e.g. issue in Github or through a W3C group such as the Improving Web Advertising Business Group or the Private Advertising Technology Community Group) is valuable in helping to ensure it’s shared with other contributing developers