UK watchdog’s Privacy Sandbox review leaves Chrome cookies in place through 2026
Daniel Simon ·
Google’s plan to retire third party cookies from Chrome has remained stalled through 2026 under the UK Competition and Markets Authority’s oversight program. The drawn out process has kept the status quo in web advertising and limited the rollout of Google’s alternative targeting tools.
The CMA has required Google to seek approval before deprecating cookies since accepting legally binding commitments in 2021. In an April 2024 update, the regulator said it was not satisfied that Privacy Sandbox proposals would prevent self preferencing or protect competition across ad tech. Google paused a limited cookie phaseout soon after and has not resumed a broader rollout.
What the documents show
Alphabet’s Form 10 Q for the quarter ended September 30, 2026 states that changes to Chrome and advertising products remain subject to ongoing regulatory review in the United Kingdom. The filing warns that required modifications or delays could affect the company’s products and financial results. Alphabet also notes that it may be unable to proceed with certain product changes until regulatory concerns are resolved.
Chrome disabled third party cookies for a small share of users in early 2024 as a test, then delayed expansion pending feedback from the CMA and the UK Information Commissioner’s Office. Google’s developer posts at the time cited the UK process as the gating factor. The CMA has continued to publish assessments of Sandbox proposals such as Topics, Protected Audience and Attribution Reporting, focusing on whether they shift power toward Google’s owned and operated services.
Industry submissions to the CMA’s process, including from publisher and ad tech trade groups in 2024, argued that the proposed APIs would reduce the effectiveness of independent ad buying while leaving Google’s signed in and app based data assets intact. The regulator’s public updates flagged concerns about measurement, abuse prevention and the risk that browser level controls could disadvantage rivals in auctions and remarketing.
Why it matters now
With third party cookies still active in Chrome, ad spend across the open web has avoided a sharp break in targeting and measurement. That outcome has benefited Google’s ads business, which leans on strong performance in Search, YouTube and Chrome based reach. It has also extended uncertainty for publishers and independent ad tech firms that invested to support Sandbox APIs that are not yet broadly viable.
The delay lands as privacy enforcement tightens elsewhere. Under the EU’s Digital Markets Act, designated gatekeepers face separate obligations on self preferencing and access to core platform functionality. EU inquiries into ad tech conduct and app distribution run in parallel to the UK process, creating overlapping compliance risk for Google if changes in one jurisdiction alter competitive dynamics in another.
What happens next depends on the CMA’s competition tests. The authority has said it will not permit deprecation until it is confident that Chrome changes do not harm rivals. Alphabet’s latest filing lists timing as uncertain. Any approval path will require further technical trials and public reporting before Chrome can retire cookies at scale. That pushes meaningful change for web advertising into an open ended timeline while regulators continue to examine how browser level design choices shift market power.