Google Antitrust Ad Tech Changes

On September 2, 2026, US District Judge Leonie Brinkema of the Eastern District of Virginia ruled that Google will not have to sell its advertising technology business, but she ordered the company to change how it operates the systems behind its digital ad monopoly. The decision denied the Justice Department’s request to divest AdX, the ad exchange, and DoubleClick for Publishers (DFP), the ad server, now combined into a single product called Google Ad Manager. Instead, Brinkema accepted most of the behavioral remedies proposed by the parties, with modifications by the Court, according to a preview of her ruling. The full opinion, detailing exactly what Google must change, remains sealed for 14 days while the parties review it for redactions.

Key Takeaways

• Judge Brinkema rejected the DOJ’s demand that Google divest its AdX exchange and DFP ad server, marking the third unsuccessful Big Tech breakup attempt by US enforcers.
• Google must implement most of the parties’ proposed behavioral remedies, which focus on how it runs auctions inside Google Ad Manager.
• The proposed changes include sharing real-time bid data with competing ad servers, ending first-look and last-look advantages, and giving publishers per-bidder price floors.
• The full remedy order is sealed for 14 days; Google has announced it will appeal the underlying April 2025 liability ruling.
• For publishers and advertisers, the real impact depends on enforcement, not just the order’s written terms.

What the Judge Ordered on September 2, 2026

The ruling concludes the remedy phase of United States v. Google LLC, the ad tech case the DOJ and a coalition of state attorneys general filed in January 2023. In April 2025, Brinkema found that Google holds illegal monopolies in two markets: servers that host publisher ads and ad exchanges that connect buyers and sellers. She wrote at the time that Google’s anticompetitive conduct “substantially harmed Google’s publisher customers, the competitive process, and, ultimately, consumers of information on the open web.”

The September decision addressed only remedy, not liability. The DOJ argued that Google could not be trusted to operate an ad exchange after years of exclusionary conduct, and that a forced sale would be a simpler, less risky solution. Google responded that divestiture would be technically difficult and harm small publishers who rely on its tools. Brinkema agreed with Google on the breakup issue but still required changes. She adopted most of the behavioral remedies proposed by both sides, designed to open Google’s ad stack to competition without breaking it apart.

Google’s vice president of regulatory affairs, Lee-Anne Mulholland, described the outcome as a win, telling reporters the company was “very pleased the Court rejected the DOJ’s proposal to break apart tools that help small businesses reach new customers and grow.” The DOJ said in a statement that it was “pleased that the Court ordered substantial relief” and that it is “evaluating appropriate next steps.”

The Behavioral Remedies in Detail

The specifics of the final order are not yet public, but the remedies are well documented because Google filed its own proposal in May 2025, before the remedy trial. In that filing, Google offered a set of fixes that directly respond to the conduct the court found unlawful. Those proposals, which appear to form the core of what Brinkema accepted, focus on three changes to Google Ad Manager:

• Share real-time bid amounts. Google proposed making real-time bid amounts for open-web display ads sold through AdX available to all competing publisher ad servers. This would let a publisher using a non-Google ad server see what AdX demand is actually bidding, removing the information gap that critics say locked publishers into Google’s stack.
• Deprecate Unified Pricing Rules. Google offered to remove Unified Pricing Rules for open-web display ads, which would allow publishers to set different price floors for different bidders when using Google Ad Manager. Currently, a publisher typically sets one floor across all demand sources; per-bidder floors would let publishers weigh bids from competing exchanges differently.
• End first-look and last-look advantages. Google committed to stop using “first look” and “last look” privileges for open-web display ads. First Look gave Google’s AdX first right of refusal on a publisher’s ad space, while Last Look let Google track competitors’ bids and top them. Google says these auction dynamics were phased out of Google Ad Manager years ago.

The DOJ, by contrast, had pushed for more aggressive structural remedies, including requiring Google to open-source parts of DFP. Some Google critics also suggested forcing AdX into Prebid.org, the open-source header-bidding framework, so it would compete on equal terms with other exchanges. Google showed openness to that idea during the remedy phase, but the final order does not appear to have gone that far.

Because AdX and DFP no longer exist as separate products, the remedies will apply through Google Ad Manager, the combined platform that now includes both the exchange and the publisher ad server. This means any change to how Ad Manager runs auctions affects how billions of open-web display impressions are bought and sold.

Why Brinkema Rejected the Breakup

Brinkema’s reasoning, explained during the remedy phase, reflects her view that a forced breakup would cause more harm than good. She noted that disrupting AdX or DFP could hurt small publishers who currently use the ad server for free. She also pointed out that if another company, such as Microsoft, acquired AdX, it could create new complications.

Most importantly, she argued that behavioral fixes would take effect faster than divestiture followed by years of appeals. A forced sale would likely have been tied up in court for years, delaying market changes while Google and the DOJ litigated terms. Behavioral remedies, by comparison, can be implemented while an appeal proceeds.

That reasoning did not satisfy Google’s critics. Jay Friedman, CartographAI co-founder and former Goodway Group CEO who testified as a DOJ witness during the remedy trial, told AdExchanger that the ruling left a fundamental question unanswered: “What is a web publisher to do if it wants to use a different ad server but still get Google’s buy-side demand?” Sacha Haworth, executive director of the Tech Oversight Project, was more direct, saying it “takes an Olympic level of mental gymnastics to find that Google is operating an illegal monopoly and then decide to do nothing about it.”

PubMatic, an SSP competing with AdX, took a more measured stance, saying it expects the “Court’s adoption of behavioral remedies should establish a level playing field for all market participants” and that focusing on behavioral fixes “will likely provide a faster path to address ongoing competitive harms from Google’s illegal monopoly.”

The Case Timeline and Bigger Antitrust Picture

The September ruling is the third recent instance where a US court rejected a government attempt to break up a major technology company. In August 2024, Judge Amit Mehta found that Google’s search business operated an illegal monopoly, but he stopped short of ordering divestiture of the Chrome browser and Android operating system, instead requiring Google to end exclusive default-placement deals and share certain search data with competitors. Google is currently appealing those search remedies.

In the Meta case, a federal judge in Washington last year rejected the Federal Trade Commission’s attempt to force the company to sell Instagram and WhatsApp. This pattern has raised questions about whether courts are prepared to limit the concentration of power in the technology industry. As one former media buyer told AdExchanger, even a trust-buster like Teddy Roosevelt “would probably be appalled by the judiciary’s lack of courage.”

Google has said it will appeal the April 2025 liability finding, so the case is far from over even after the remedy ruling. The DOJ is also considering whether to appeal the remedy decision. The conduct at issue predates the AI era, but the case now involves a market that Google itself has been changing with generative AI search and automation tools, which some industry observers say the court did not fully consider.

What It Means for Publishers and Advertisers

For publishers, the stakes are clear. Google Ad Manager is the tool most of the open web uses to sell display inventory, and the exchange connects buyers and sellers in every auction. The behavioral remedies, if enforced as proposed, would reduce the information and timing advantages that critics say let Google steer transactions to its own exchange.

The most significant change is likely the requirement to share real-time bid amounts with competing ad servers. Currently, a publisher that wants to use a competing ad server while still accessing AdX demand faces a structural disadvantage: it cannot see what AdX is bidding in real time the way a publisher inside Google’s stack can. Opening that data would make it easier for publishers to run header-bidding or multi-server setups without losing access to Google’s demand.

The removal of unified pricing floors would give publishers more control over how they value different demand sources. Instead of applying one floor across all bidders, a publisher could set a higher floor for a low-quality bidder and a lower one for a preferred exchange, which could increase revenue for publishers familiar with their inventory. The downside is complexity: per-bidder floors add operational overhead and require publishers to manage more settings than the single floor they use today.

Compliance is also important for any business running an ad monetization stack. Even with the order in place, enforcement depends on the court and Google’s engineering teams. The DOJ warned during the remedy phase that Google could still find ways to “manipulate the computer algorithms that are the engine of its monopolies in ways too difficult to detect.” Whether behavioral remedies change outcomes will depend on how transparent Google is in implementation and how closely the court monitors compliance.

For advertisers, the immediate effect is likely limited. The systems involved handle display advertising on the open web, which is a small part of Google’s overall ad revenue. Google has said the ad exchange technology targeted in the case handles roughly 55 million requests per second, and the company warned that “this is technology that absolutely has to keep working for consumers.” Analysts estimate Ad Manager represented about 4.1 percent of Google’s revenue and 1.5 percent of its operating profit in 2020, though more recent figures were redacted from court documents. The ruling is expected to slow Google’s growth in this segment rather than reverse it.

The larger question, as some industry voices noted, is whether the case shows the limits of US antitrust enforcement against platform companies. Two federal judges have now found that Google runs illegal monopolies, yet neither ordered a breakup. If Google wins on appeal, the practical lesson for the ad tech industry may be that behavioral remedies, not divestitures, are the highest level of intervention US courts will impose on dominant platforms.

Frequently Asked Questions

What did the judge order Google to do in September 2026?

Judge Brinkema rejected the DOJ’s request to force Google to sell its AdX ad exchange and DFP ad server, but ordered Google to adopt most of the parties’ proposed behavioral remedies for how it runs its ad business. The full specifics are sealed for 14 days.

Why did the US antitrust lawsuit target Google’s ad tech?

The DOJ and states sued in 2023, arguing Google illegally monopolized markets for publisher ad servers and ad exchanges by tying its products together and using features like First Look and Last Look to steer transactions to its own exchange. In April 2025, the court agreed.

What is Google Ad Manager?

Google Ad Manager is the combined product that includes both the AdX ad exchange and DoubleClick for Publishers (DFP) ad server. Publishers use it to sell display ad space, and the exchange connects them to advertisers.

Will Google have to sell its ad business?

No. The September 2026 ruling rejected the DOJ’s divestiture request. Google will keep AdX and DFP, but must change some of its business practices.

What happens next in the case?

Google has said it will appeal the April 2025 liability finding, and the DOJ is considering whether to appeal the remedy ruling. The full remedy opinion is expected to be unsealed about two weeks after the September 2 decision.

Related reading on this site: For broader context on how platform regulation and infrastructure decisions intersect, see our analysis of Alphabet’s 2024 annual report and AI revenue recognition, our coverage of Google’s $920 million monthly SpaceX compute deal, and our examination of Chrome’s first zero-day of 2026. For the regulatory angle on platform power, see how antitrust and rate decisions shape tech valuations.