What happened to Google Privacy Sandbox?
Google wound down Privacy Sandbox. After deciding to keep third-party cookies in Chrome, it announced in October 2025 that it was retiring most Privacy Sandbox technologies, including the Topics API, Protected Audience API and Attribution Reporting, citing low adoption and ecosystem feedback. Only a few narrower features, such as CHIPS, FedCM and Private State Tokens, continue.
The Privacy Sandbox was meant to replace cross-site tracking with browser-based APIs: the Topics API for interest-based ads, the Protected Audience API for on-device remarketing auctions, and aggregated measurement. The UK Competition and Markets Authority oversaw the project because of concerns it would entrench Google; it released Google from its commitments after cookies were kept.
The lesson for buyers: industry-wide identity replacements are fragile. Durable approaches rely on consented first-party data, contextual targeting, data clean rooms and measurement that does not depend on any single browser's policy.