Google's multi-year project to replace third-party cookie functionality with privacy-preserving alternatives built into Chrome. Topics API was meant to replace interest-based targeting. Protected Audience was meant to replace remarketing. Attribution Reporting was meant to replace conversion measurement. The industry's skepticism was structural: Google was building the replacement for a system it also benefits from, inside a browser it controls. In April 2025, Google decided to keep third-party cookies in Chrome. In October 2025, it retired most of the Sandbox APIs after adoption stalled. The Privacy Sandbox was not wrong as an engineering direction. As a governance arrangement, the market never bought in.
Ad tech glossary
Privacy Sandbox
Technical definition
Google's initiative to build privacy-preserving web standards for advertising in Chrome. In October 2025, Google retired most of its APIs, including Topics, Protected Audience and Attribution Reporting.
The ADLINGO translation
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Related terms
- Ad Rank
- Broad Match Modifier (RIP)
- Discovery Campaigns
- FLEDGE (First Locally-Executed Decision over Groups Experiment)
- FLoC (Federated Learning of Cohorts)
- Local Service Ads
- Match Types
- Maximize Conversion Value
- Negative Keywords
- Performance Max
- PRAM (Partnership for Responsible Addressable Media)
- Project Rearc
Where this shows up
Google Monopoly for the CMO
When asked what today's ruling against Google means for advertisers, here is what I say. (Without making a prediction about a breakup.)
Monetizing AI Overviews
Ads in Google's AI Overviews are already natively integrated for immediate shoppability. What does this mean for advertisers, publishers, and the future of the ad supported Internet?
