Privacy Sandbox

The Privacy Sandbox was an initiative led by Google which aimed to create web standards for websites to access user information without compromising privacy. Announced in 2019, the core purpose of the project was to facilitate online advertising by sharing a subset of user private information without the use of third-party cookies. The technology included Topics API (formerly Federated Learning of Cohorts or FLoC), Protected Audience, Attribution Reporting, Private Aggregation, Shared Storage, and Fenced Frames as well as other proposed technologies like IP Protection, Related Website Sets, CHIPS, and Bounce Tracking Mitigation. On September 7, 2023, Google announced general availability of majority of proposed APIs. In April 2025, Google officially discontinued the Privacy Sandbox initiative, citing lack of interest from websites, low and dropping adoption and regulatory pressure.

The initiative has been described as anti-competitive and generated an antitrust response due to concerns that the introduced proposals limited tracking through traditional methods and pushed advertisers to use Google as a middleman in order to show advertisements.