Meet Topics API: Google’s New Privacy Sandbox Replacing FLoC

Google announced Topics, a new Privacy Sandbox proposal for interest-based advertising. Topics was informed by their learning and widespread community feedback from their earlier FLoC trials and replaces their FLoC proposal.

Google started the Privacy Sandbox initiative to improve web privacy for users, while also giving publishers, creators and other developers the tools they need to build thriving businesses, ensuring a safe and healthy web for all. The company knows that advertising is critical for many businesses, and is a key way to support access to free content online.

According to Google, with Topics each user’s browser determines a handful of topics, like “Fitness” or “Travel & Transportation,” that represent the user’s top interests for that week based on her/his browsing history. Topics are kept for only three weeks and old topics are deleted. Topics are selected entirely on the user’s device without involving any external servers, including Google servers. When you visit a participating site, Topics picks just three topics, one topic from each of the past three weeks, to share with the site and its advertising partners. Topics enables browsers to give you meaningful transparency and control over this data, and in Chrome, they’re building user controls that let you see the topics, remove any you don’t like or disable the feature completely.

More importantly, topics are thoughtfully curated to exclude sensitive categories, such as gender or race. Because Topics is powered by the browser, it provides the Internet user with a more recognizable way to see and control how her/his data is shared, compared to tracking mechanisms like third-party cookies. And, by providing websites with the user’s 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.

With Topics, Google can provide data for advertisers while preserving the users’ privacy more than when using cookies. Also, users get the freedom to edit which topics are shared and even disable the feature completely, giving them more control over their data.

To learn more about the details of the Topics proposal, including other design features that preserve privacy, see an overview on or read the full technical explainer. Soon, Google will launch a developer trial of Topics in Chrome that includes user controls, and enables website developers and the ads industry to try it out. The final design of the user controls and the other various technical aspects of how Topics works will be decided based on the user’s feedback and what we learn in the trial.

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This is a busy time for the Google Privacy Sandbox. they recently worked with the U.K.’s Competition and Markets Authority (CMA) to offer revised commitments to ensure our proposals are developed in a way that works for the entire ecosystem, and later this week, they’ll be sharing more details about the FLEDGE and measurement technical proposals with developers. Google’s Privacy Sandbox is one of the most ambitious, important efforts the company has ever undertaken, and we’re profoundly grateful for the engagement, feedback and partnership from everyone who’s participated.

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Ben Galbraith, Senior Director, Product at Google
We need to make sure that whatever we do does not result in us giving an unfair advantage or favoring our advertising business.

“We need to make sure that whatever we do does not result in us giving an unfair advantage or favoring our advertising business, and that’s the underlying constraint that dictates how we think about this,” Ben Galbraith, who leads product for Google Chrome’s web platform team, told AdExchanger.

“You can imagine an alternative world where we just, you know, did something without getting any feedback and just launched it into the world,” Galbraith said. “And that’s pretty close to the opposite of the approach that we’ve taken here.”