GroupM Launches Comprehensive Post-Cookie Readiness Program Testing Google’s Privacy Sandbox

  In joint initiative with Google Chrome, GroupM to launch first-to-market program using Privacy Sandbox APIs, helping accelerate readiness for the planned third-party cookie deprecation in H2 2024 

New York, London, Singapore (November 15, 2023) — GroupM, WPP’s media investment group, today announced the launch of the first and largest global post-cookie technology readiness program, in partnership with Google Chrome. This global initiative brings together GroupM clients to accelerate their understanding of Google Privacy Sandbox APIs and their use in advertising.

Participating GroupM clients will get access to the learning program to assess and improve their post-third-party cookie deprecation readiness in a real-life environment, using their own products and audiences.

“We strongly believe advertising can and should respect people’s privacy while continuing to deliver exceptional value for consumers and advertisers,” said Christian Juhl, GroupM’s Global CEO. “Since Google publicly declared their intention to deprecate third-party cookies, we’ve been collaborating closely with the Chrome team, our clients, and other partners to ensure our clients won’t miss a beat when the transition happens. The program we’re announcing today is an exciting step forward in that collaboration that will allow our clients to test existing preparations and enable us to develop new approaches where necessary.”

Key features of the program include:

  • Unified Framework: GroupM is designing a unified framework for testing, informed by the UK’s Competition and Markets Authority’s (CMA) guidance for post-cookie testing, to work collaboratively with advertisers and ad tech partners to understand plans to integrate privacy technologies, including Privacy Sandbox APIs, and overlay relevant tests wherever possible.
  • Anonymized Data: To facilitate the fullest learning opportunity for each participating advertiser, GroupM will conduct an anonymized meta-analysis across individual brand tests, in addition to a brand’s own Privacy Sandbox program. This information will be anonymized and aggregated as part of collective learnings and eventually a meta-study.
  • Accelerated Learning: Participating advertisers will get direct access to testing across GroupM alpha/betas with our global ad-tech partners. As first-to-market testers, participating clients will learn at the forefront of this industry-altering change, gaining access to GroupM’s collective knowledge.

Google Chrome plans to deprecate third-party cookies in H2 2024 in order to better protect people’s privacy online, subject to resolving any competition concerns with the CMA. To support the web ecosystem in conducting real world evaluations of products and services using the Privacy Sandbox APIs, Chrome will deprecate third-party cookies for approximately one percent of Chrome users at the beginning of Q1 2024. It is critical that advertisers accelerate the testing of alternative approaches and better understand their readiness, in order to maintain marketing effectiveness in a world without third-party cookies. The outcome of this global program will guide GroupM’s clients on targeting, optimization, and measurement of digital investment across display and video.

For advertisers who might not be fully prepared for the deprecation of third-party cookies, this program gives participants an opportunity to pave the way for how brands target, optimize, and measure without them. This program is one of the many ways GroupM will help clients adapt their marketing strategy to maintain relevance and effectiveness in a post-cookie world.

“This program is a key step in our ongoing efforts to ready the industry for the transition to the post-cookie era,” said Anthony Chavez, Vice President, Privacy Sandbox, Google. “GroupM is well equipped to help advertisers with their third-party cookie deprecation preparation efforts. Along with their ad tech providers, this initiative will help GroupM’s clients as they work to integrate the capabilities that the Privacy Sandbox provides. Through this readiness program, GroupM and its clients will play an important role in helping to create a more private internet for everyone.”

By partnering with Google Chrome, GroupM will be able to better guide its clients in shaping digital strategies that leverage the Privacy Sandbox technologies. GroupM and participating clients will benefit from learnings ahead of the deadline for the planned deprecation of third-party cookies in Chrome. They can also provide feedback on Privacy Sandbox features, and, alongside key ad tech partners, help define new internet privacy measures that enable publishers and developers to keep online content free.

The Privacy Sandbox program is being conducted using existing media plans and budget, with no mandatory additional investment, thereby optimizing existing campaigns in a future-proofed and privacy-centric manner.

Advertisers who are interested in learning more about the program can contact [email protected].


About GroupM

GroupM is WPP’s media investment group and the world’s leading media investment company with a mission to shape the next era of media where advertising works better for people. The company is responsible for more than $60 billion in annual media investment, as measured by the independent research bureau COMvergence. Through its global agencies Mindshare, Wavemaker, EssenceMediacom, and mSix&Partners, and cross-channel performance (GroupM Nexus), data (Choreograph), entertainment (GroupM Motion Entertainment) and investment solutions, GroupM leverages a unique combination of global scale, expertise, and innovation to generate sustained value for clients wherever they do business. Discover more at

Media Contact

Jared Baiman
Associate Director, Global Communications
[email protected]