Google's proposal for interest-based targeting after third-party cookies. The user's browser holds the interest group data locally. The auction runs in a sandboxed environment on the device. Publishers and advertisers get outcome signals without accessing individual browsing history. FLEDGE was later renamed Protected Audience, and Google retired Protected Audience along with most of the Privacy Sandbox in October 2025. Understanding the design still helps make sense of the problem it was trying to solve.
Ad tech glossary
FLEDGE (First Locally-Executed Decision over Groups Experiment)
Technical definition
Part of Google's Privacy Sandbox, a proposal for interest-based advertising that keeps user data local to the browser.
The ADLINGO translation
Get the full Mega Glossary as a PDF
Nearly 200 ad tech terms, translated. Plus the ADLINGO newsletter every Tuesday. Free.
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?
