TLDR
Google must open key ad tools to rival systems and accept a six year court monitor after losing a US antitrust case. The judge refused to break up the business, but publishers and buyers using Google Ad Manager may get more room to use competing tools.
KEY TAKEAWAYS
Google kept its ad tech stack. A U.S. judge changed the way rival tools can connect to it, for publishers and buyers still using Google Ad Manager every day.[1]
Judge Leonie Brinkema ordered Google to connect its ad exchange and publisher ad server to Prebid, let publishers take their own data with them, and accept a six year antitrust monitor.[1] The court refused the Justice Department’s push to force a breakup of the ad tech business.[2]
The order
The court ordered Google to create and support integrations between AdX and Prebid, and between DFP and Prebid, so publishers can route real time bids through competing header bidding systems.[1] Google Ad Exchange (AdX) is Google’s real time ad exchange. DoubleClick for Publishers (DFP) is its publisher ad server and now sits inside Google Ad Manager.[1]
The court also required Google to allow publishers to access and export their own data held in DFP and AdX, helping them move to rival ad tech providers.[1] Judge Brinkema also ordered Google’s AdWords platform to bid into AdX and DFP in a non discriminatory way, without preference tied to Google’s ownership of those tools.[1]
A court appointed antitrust compliance monitor will oversee Google’s compliance with these behavioural remedies for a period of six years.[1] Judge Brinkema said, “The remedies will be sufficient to effectively pry open to competition the ad tech markets that were injured by Google’s unlawful conduct, and prevent Google from reverting to anticompetitive conduct in these markets.”[3]
No breakup
The Justice Department asked for structural relief, including divestiture of Google’s publisher ad server and ad exchange products. Judge Brinkema chose conduct rules instead.[2]
Lee Anne Mulholland, Google’s vice president for regulatory affairs, said, “The DOJ’s additional proposals to force a divestiture of our ad tech tools go well beyond the Court’s findings, have no basis in law, and would harm publishers and advertisers.”[4]
Australia angle
The Justice Department and eight states filed the case in January 2023, saying Google monopolised the open web display publisher ad server and ad exchange markets and unlawfully tied DFP to AdX.[5] Judge Brinkema ruled in April 2025, after trial, that Google had wilfully maintained monopoly power in both markets and had unlawfully tied the products.[2]
Australian publishers and media buyers still rely on Google Ad Manager for inventory management and auction access. The order lets rival bidding systems plug into that workflow more directly, and it lets publishers take their own data out more easily.[1]
| Stage | What happened | Source |
|---|---|---|
| January 2023 | Justice Department and eight states filed the antitrust complaint against Google | DOJ case page |
| April 2025 | Judge found Google maintained monopoly power and unlawfully tied DFP to AdX | Court ruling |
| September 2026 | Court ordered interoperability, data export and a six year monitor | DOJ release |
Google now has to let rivals work inside parts of its existing ad tech setup. The monitor will oversee compliance for six years.[1]
SOURCES & CITATIONS
FREQUENTLY ASKED QUESTIONS
What did the judge order Google to change?
Did the court break up Google’s ad tech business?
Why does this matter for Australian publishers and buyers?
Xaviery Malinao writes for Prompt the Market on how brands and agencies are adapting to answer engines, drawing on Bushnote's work with clients across search, AI search and content.
