Federated Learning of Cohorts
Federated Learning of Cohorts (FLoC) is a type of web tracking. It groups people into "cohorts" based on their browsing history for the purpose of interest-based advertising. FLoC was being developed as a part of Google's Privacy Sandbox initiative, which includes several other advertising-related technologies with bird-themed names.: 48 Despite "federated learning" in the name, FLoC does not utilize any federated learning.
| Abbreviation | FLoC |
|---|---|
| Status | Replaced by Browsing Topics API |
| Year started | 2019 |
| Organization | |
| Series | Privacy Sandbox |
| Website | privacysandbox |
Google began testing the technology in Chrome 89 released in March 2021 as a replacement for third-party cookies. By April 2021, every major browser aside from Google Chrome that is based on Google's open-source Chromium platform had declined to implement FLoC. The technology was criticized on privacy grounds by groups including the Electronic Frontier Foundation and DuckDuckGo, and has been described as anti-competitive; it generated an antitrust response in multiple countries as well as questions about General Data Protection Regulation compliance. In July 2021, Google quietly suspended development of FLoC; Chrome 93, released on August 31, 2021, became the first version which disabled FLoC, but did not remove the internal programming.
On January 25, 2022, Google officially announced it had ended development of FLoC technologies and proposed the new Topics API to replace it. Brave developers criticized Topics API as a rebranding of FLoC with only minor changes and without addressing their main concerns.