(Bloomberg) -- Alphabet Inc.’s Google will phase out third-party cookies for 1% of the users of its Chrome browser in the first quarter of 2024, a key step in a plan that will upend how advertisements are targeted on websites.

The company reiterated its pledge to phase out third-party cookies in Chrome more broadly in the second half of 2024. Cookies are software that help track users as they browse the internet, providing marketers a way to target ads based on a person’s web interests.

“To get ready for the web without third-party cookies, it’s important that the ecosystem prepare in advance,” Anthony Chavez, a Google vice president, wrote in a blog post Thursday announcing the move. He said that phasing out the cookies for a small subset of users will “support developers in conducting real world experiments that assess the readiness and effectiveness of their products.”

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Chavez said the company’s approach was designed in collaboration with the UK’s Competition and Markets Authority.

“We will continue to address comments made by the CMA, as we prepare for third-party cookie deprecation beyond 1% of Chrome users once the CMA has completed its assessment,” he said.

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