Google keeps its ad-tech stack but must open the auction machinery to rivals

A federal court has imposed the operating rules for Google’s advertising-technology monopoly case without ordering a divestiture. Judge Leonie Brinkema requires Google to decouple its AdX exchange from its publisher ad server, relax auction restrictions so rival services can interoperate, and appoint an antitrust compliance officer monitored for six years.

The remedy follows her April 2025 finding that Google illegally monopolized parts of the publisher-ad-server and exchange markets. The Justice Department wanted structural separation and 15 years of oversight; Google argued that forced sales would disrupt customers. Google plans to appeal the liability ruling.

The court’s reasoning includes a consequential market judgment: generative AI is changing advertising and search quickly enough that conduct remedies may restore competition without dismantling the business. That could be right, but it also gives Google time and control over implementation. Interoperability rules succeed only if rivals receive usable access with latency, data quality and contractual terms that let them compete. A monitor can observe compliance; it cannot by itself create an alternative ad marketplace.