Digital advertisers are pushing an alternative to web cookies that competes with a Google proposal, the latest industry effort to adjust to new curbs on how personal data is used online.

A group of ad executives and lawyers detailed an anonymous identifier on Wednesday that lets people control what ads they see on the web. The technology, called SWAN, is supported by ad-tech companies including PubMatic, OpenX and Zeta Global Corp.

There’s now a 60-day public-comment period when marketers, publishers and others in the industry can try out the system before it launches in the summer.

Google upended the sector when it announced plans last year to end third-party cookies that advertisers rely on to track users and measure the performance of digital marketing campaigns. The move is being examined by antitrust regulators.

The withdrawal of third-party cookies leaves a vacuum that SWAN can plug and “address problems that we all see with the unfettered” use of data for advertising, said James Rosewell, a tech entrepreneur who helped found the project in early 2020. He describes it as a new utility for publishers and advertisers that don’t want to rely on Google.

Google’s new plan, known as FLoC, replaces third-party cookies with a system that puts users into groups, or cohorts, based on common interests. Users can opt out.

SWAN works differently. When people first visit a website in the SWAN network, they will be asked to give consent for all publishers that use SWAN to show them ads. Personalized ads is one option, but not required. User preferences are then stored in the SWAN network registry and shared with other SWAN participants so individuals’ access to online content continues uninterrupted. People can change preferences anytime on any of the websites and that will be automatically updated for all sites in the network.

—Bloomberg News