Google’s Privacy Sandbox may have receded from the spotlight, but one of its central ideas — browser-based ad measurement — is re-emerging through the World Wide Web Consortium (W3C). Here’s what marketers, publishers, and ad tech companies need to know.Google’s decision to step back from deprecating third-party cookies within Chrome, the market’s most popularly used web browser, in early 2025 led to a sigh of relief around the industry, even if it was tinted with some chagrin.
However, it didn’t necessarily bring the debate over browser-based ad measurement to an end; instead, it shifted it into a different forum: W3C, a web standards group where erudite professionals from some of the digital media industry’s leading lights quietly debate and help shape the future of the industry.
The long goodbye continues
Currently, there is a proposal under development within W3C — the web standards body responsible for technologies such as HTML and URLs — and has been incubated in recent months within the web standards body’s Private Advertising Technology Working Group, or “PAT Working Group” to those within it.
Dubbed “Attribution API,” it aims to create a common way for browsers to measure whether digital advertising leads to outcomes such as purchases, app installs, or sign-ups, while limiting the amount of information shared about individual users — sentiments that will sound familiar to those who kept abreast with Google’s privacy efforts in the early 2020s.
