Google has been ordered to open up parts of its online advertising technology to rivals, but the company avoided the most severe remedy sought by US antitrust enforcers: a forced sale of its AdX advertising exchange.

US District Judge Leonie Brinkema ordered a package of behavioural remedies aimed at reducing the tight links between Google’s publisher ad server, ad exchange and advertising demand tools. The measures include broader interoperability with rival ad-tech services, publisher data portability and six years of compliance monitoring.

The ruling follows the court’s April 2025 finding that Google unlawfully monopolised key parts of the open-web advertising technology market. Google has said it plans to appeal aspects of the case.

What the court ordered Google to change

According to the US Department of Justice, Google must build and support integrations between AdX and Prebid, as well as between Google’s DFP publisher ad server and Prebid. Prebid is an open-source technology widely used by publishers for real-time advertising auctions.

The order also requires AdX to submit real-time bids to competing publisher ad servers. That matters because publishers previously faced strong incentives to keep both their ad server and exchange relationship inside Google’s stack.

Google must additionally make it easier for publishers to access and export their own data from DFP and AdX. In practical terms, better data portability can reduce one of the costs that makes switching ad-tech providers difficult.

Google Ads demand must compete more neutrally

The remedies also reach Google’s advertiser demand. The Justice Department says Google’s AdWords business — now marketed as Google Ads — cannot bid preferentially into AdX or other Google-owned ad-tech products merely because Google owns both sides of the transaction.

That is potentially important for rival exchanges and publisher tools because demand from Google Ads represents a valuable source of advertiser spending. The court’s goal is not to remove that demand from Google’s products, but to reduce discriminatory advantages that can make competing infrastructure less attractive.

For advertisers trying to understand how their own campaigns compare with peers, FlyingEze recently covered Google Ads’ Spend Benchmarks report . The antitrust ruling is a different issue: it focuses on the underlying market infrastructure through which publishers, advertisers and intermediaries buy and sell open-web display advertising.

Why there is no forced breakup

The Justice Department had sought structural relief that would have required Google to sell AdX and potentially other ad-tech assets. The court rejected that request, concluding that behavioural remedies could address the competitive harms without ordering divestiture.

That means Google keeps control of its core ad-tech businesses for now. The significance of the ruling lies instead in how those products must interact with competitors.

The court also imposed a six-year compliance regime involving an independent monitor and technical committee. That period is shorter than the 15 years sought by the government, but it gives regulators a mechanism to oversee implementation rather than relying solely on one-time product changes.

What the ruling means for publishers

Publishers are among the most directly affected parties because ad servers and exchanges determine how advertising inventory is routed, auctioned and sold.

If the remedies work as intended, publishers should gain more flexibility to combine Google demand with non-Google infrastructure rather than choosing between an all-Google setup and losing access to some valuable demand sources.

Better interoperability could also lower switching costs. A publisher considering a rival ad server may find migration more practical if bidding, data export and auction compatibility improve.

However, the effects will depend on implementation. Technical integrations can be formally available while still being slower, less complete or harder to operate than first-party connections. That is one reason the monitoring provisions matter.

What the ruling means for advertisers and ad-tech rivals

Advertisers are less likely to notice an immediate change in a campaign dashboard. The ruling operates deeper in the advertising supply chain.

Over time, stronger competition among exchanges and publisher tools could influence fees, auction transparency, product innovation and the number of viable routes through which advertisers can reach publisher inventory.

For independent ad-tech companies, the most important provisions are those that reduce privileged connections between Google-owned products. Access to real-time bids and advertiser demand can determine whether a competing platform has enough liquidity to be useful.

This is a major remedy, but not the end of the case

The ruling does not mean Google’s ad-tech business is being dismantled, and the ordered changes will not transform the market overnight.

Reuters reported that Google plans to appeal the liability finding concerning Google Ad Manager. The final impact will therefore depend on appeals, technical implementation and how strictly the compliance framework is enforced.

The broader lesson for the digital advertising industry is that regulators are increasingly focusing not only on market share but also on the technical links between platforms. In ad tech, interoperability can be as important to competition as ownership.

Sources: Reuters and the US Department of Justice .