Google has avoided a forced sale of its advertising business, but a US federal judge has ordered it to prise open the auctions at the heart of the online ad market.
The ruling, set out in a 106-page remedies opinion unsealed this week, requires Google, the search and advertising arm of Alphabet, to let rival systems connect to its technology and to share more of its auction data.
The judge let Google keep AdX, its ad exchange, which is the marketplace where display adverts are auctioned in the instant a web page loads.
What Google must change
The order targets the tactics that the court found had tilted that market in Google's favour.
Google must now run its exchange and its publisher ad server on equal terms for competitors, drop pricing rules that disadvantaged rival bidders and abandon practices that gave its own systems an early or final look at bids.
It must also build the connections that let competing ad servers, exchanges and tools work alongside its own.
How the case got here
The decision follows an April 2025 finding by Judge Leonie Brinkema, sitting in the Eastern District of Virginia, that Google had illegally maintained a monopoly over two parts of the ad-tech chain and unlawfully tied its ad server to its exchange.
The Department of Justice, joined by a group of states, had pushed for a structural fix, pressing the court to make Google sell AdX and to keep the remedies in place for 15 years.
Brinkema rejected a breakup as "neither realistic nor needed", concluding that changes to Google's conduct would be enough to restore competition.
Six years of oversight
Citing what she described as a lack of trust that Google would comply, the judge ordered the company to appoint an internal antitrust compliance monitor.
That oversight, backed by a technical committee, will run for six years, and the court can extend it.
Google has said it will appeal the underlying monopoly ruling, and the two sides have been given time to submit a joint proposed final judgment.
The stakes are large, because the auctions covered by the case help decide how billions of dollars in online advertising are bought and sold.
