Only four months after the announcement of Federated Learning of Cohorts, FLoC, it appears that Google Chrome will be the only browser that accepts them. As of April 2021, Firefox, Microsoft Edge, Safari and Brave have all opted out of the third-party cookie alternative. Google began testing the feature on Chrome with about 0.5% of users before ultimately rolling it out to all users on March 31, 2021.

These opt outs do not come as too much of a surprise, seeing as all the opted-out browsers have been quick to enforce the removal of third-party cookies. Apple announced Safari’s Intelligent Tracking Prevention that blocks all third-party cookies over a year ago in March 2020. Firefox is blocking all third-party cookies by default with its Enhanced Tracking Protection.

While it does not come as a surprise that these browsers opted out of Google’s FLoC, it does continue to leave the door open to a widely used alternative to third-party cookies. Opera, a lesser-used browser that has a history of being privacy friendly, released a statement to theverge.com saying it would not be enabling FLoC on its browser in its current form but are discussing new and better privacy-preserving advertising alternatives to cookies including FLoC.

For the time being, it’s a no to Google’s alternative from Opera and other bigger players, but the option that a form of FLoC could work in the future is exciting for the digital advertising industry.