Google keeps AdX and DFP as Judge Brinkema orders behavioral fixes, not a breakup

US District Judge Leonie M. Brinkema of the Eastern District of Virginia ruled on 2 September 2026 that Google must change how its advertising technology runs auctions. She rejected the Department of Justice's demand that the company sell AdX, its ad exchange. The order was short. The reasoning behind it is under seal.

The case is United States v. Google LLC, No. 1:23-cv-108. It follows Brinkema's April 2025 liability finding that Google illegally monopolised the publisher ad server market, where it held roughly 91% of worldwide market share by impressions served, and the open-web display ad exchange market, where AdX charged a consistent 20% take rate for over a decade. She also found Google illegally tied the two products together.

What the judge actually ordered

According to reporting on the order and the parties' pre-ruling proposals, the court adopted or closely tracked four behavioral obligations. The public order runs two pages and does not spell out the details. The full list waits on the unsealed memorandum opinion.

• First look, ended. Since around 2010, AdX saw every publisher impression before rival exchanges could bid, and could buy it at or above the publisher's floor. Competitors only got what AdX declined. That is now prohibited.
• Last look, ended. AdX could see the highest bid from rival exchanges before submitting its own. Brinkema's earlier ruling, citing the Index Exchange complaint filed in November 2025, described this as opening the sealed bid envelope before bidding. AdX could outbid the leader by one cent, every time. Now banned.
• Unified Pricing Rules deprecated. Google's 2019 rules forced publishers to apply the same minimum price to every bidder, including AdX. Removing them restores publishers' ability to set different floors for different buyers.
• Real-time bid sharing. AdX must make its bid amounts available to rival publisher ad servers in real time. That answers the information advantage that made AdX close to mandatory for publishers chasing Google's buy-side demand.

The DOJ had asked for far more: sale of AdX within twelve months, open-sourcing of DFP's final auction logic under a neutral administrator such as Prebid.org within twelve months, and a contingent divestiture of remaining ad server components if competition did not recover within three years. Government lawyers argued in closing that promises from a company whose conduct was, in their words, buried in computer codes and algorithms could not be trusted. Only divestiture, they said, could eradicate the monopolies root and branch.

Google countered that breaking up a system handling 55 million ad requests per second would be technically unworkable and would hurt small publishers who use DFP at no charge. It proposed behavioral relief instead: real-time bid sharing, removal of the pricing rules, and compliance monitoring for six years. The parties proposed different monitoring windows, Google at six years and the government at ten. The court's chosen duration remains under seal until the final judgment filing, due 2 October 2026.

Why the breakup was refused

Brinkema found that the risk and delay of a forced sale outweighed the benefit. She was sceptical that a qualified buyer for AdX could be found without years of added litigation. Reporting on the closing arguments says she also flagged that time was somewhat of the essence, given how fast AI is reshaping digital advertising: a lengthy divestiture could be obsolete before it finished.

The outcome mirrors the search monopolisation case before Judge Amit Mehta in the District of Columbia. There the DOJ's request to force a sale of Chrome was rejected in September 2025 in favour of data-sharing and choice remedies. That case is on appeal, with Google and the DOJ, joined by 38 state attorneys general, each challenging parts of Mehta's order.

It is also the third consecutive rejection of a US antitrust enforcer's bid to break up Big Tech. A federal judge in Washington last year declined to make Meta sell Instagram and WhatsApp, saying the FTC had failed to prove Meta held a monopoly in a social media market that had shifted since the case was brought in 2020. The FTC has appealed. Cases against Amazon and Apple have not yet gone to trial.

Financially, the ad tech business barely moves Alphabet's numbers. Google's ad tech unit brought in roughly $30 billion last year, about 8% of Alphabet's total revenue. That revenue has declined for 16 consecutive quarters, and analysts estimate it accounts for less than 1% of profit. Ad Manager alone represented 4.1% of Google's overall revenue and 1.5% of operating profit in 2020, according to Wedbush research and analysis of court documents. More recent figures were redacted.

Google's shares pared gains slightly after the ruling and were up 0.6%, according to Reuters.

What stays the same

Google still owns the dominant publisher ad server and the dominant ad exchange. It still runs the auction software that decides which impression goes to which buyer. It still controls the data pipeline that tells both sides of the market how to price. The order changes the rules of the auction without changing who owns the machinery that runs it.

Jay Friedman, a co-founder of the ad-tech advisory firm CartographAI who testified for the DOJ at the remedies trial, put the residual problem as a question, according to Tech Times: what is a web publisher to do if it wants to use a different ad server but still get Google's buy-side demand? Real-time bid access is supposed to answer that. Whether it does will be determined in practice, not in the courtroom.

Google framed the ruling as a win. Lee-Anne Mulholland, the company's vice president for regulatory affairs, said 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 it was pleased the court ordered substantial relief, adding that it was one step closer to restoring competition and evaluating appropriate next steps.

Critics of the conduct-only approach were less impressed. Sacha Haworth, executive director of The Tech Oversight Project, said the rulings prove that the courts alone will not save us from Big Tech. The advocacy group has proposed legislation aimed at restoring competition in digital advertising.

The full reasoning stays sealed for fourteen days while both sides review it for confidential business information. Reporting citing the docket says that window closes around 16 September 2026. Both parties have thirty days from the order to confer and file a jointly proposed final judgment. Until those documents land, the enforceable details that advertisers, publishers and ad-tech vendors must comply with are still being finalised.