Privacy Update: Google Privacy Sandbox

Privacy Update: Google Privacy Sandbox


Google had first introduced Privacy Sandbox, a series of privacy-first alternatives to third-party cookies, in early 2020. The motive behind this cookie-less world initiative was to satisfy the needs of user privacy based on browsing habits. Digital publishers were forced to be SameSite compliant as the removal of third-party cookies could reduce ad revenue by 52% and lead to less insights into conversions. Fast forward to today, Google is excited to share their proposals. They have found Privacy Sandbox technology yielding results nearly as effective as cookie-based approaches.


The first of Google’s proposals was the FLoC (Federated Learning of Cohorts) API which shifts the collection and measurement of user-level data to group-level data. FLoC essentially anonymizes the individual, which gives them the blanket of security they need. After testing through simulations, Google claims advertisers can expect to see at least 95% of the conversions per dollar spent when compared to cookie-based advertising. It will be publicly available to test in March for developers and in Q2 for advertisers.

FLEDGE (First Locally-Executed Decision over Groups Experiment) is another proposal of Google’s, which expands on the previously proposed TURTLEDOVE. It focuses on having a trusted third-party server responsible for storing information on campaign auctions and budgets. This API to help marketers bring their own servers to the table will be available later this year.

Another Privacy Sandbox proposal is the Event Conversion Measurement API which allows for the measurement of click-based conversions without using cross-site identifiers. According to Google, it helps preserve user privacy by adding noise and limiting the amount of data that gets sent from the device. They are still evaluating how to simultaneously use the API with Google’s current measurement system. As they perfect on balancing the noise and the amount of transferable data, they advise businesses to implement sitewide tagging.

The lack of user-level data can worry sites and publishers as they would not be able to authenticate the traffic. To strengthen that trust, Google opened the Trust Token API for testing last July. This will combat fraud from bots and scammers without exposing the identity of individuals.

Lastly, the Gnatcatcher API will help protect a user’s identity by providing a mechanism that hides their IP address. This API is currently in development and is open to feedback from the community.


These Privacy Sandbox proposals are currently conversation starters that will evolve as more feedback is collected. Once the testing phases are completed, it will revolutionize the industry and hopefully help digital marketers regain consumer trust.