Google Keeps AdX: Judge Rejects Ad Tech Breakup and Orders Behavioral Fixes Instead

Google will not have to sell its advertising exchange. On Wednesday, September 2, US District Judge Leonie Brinkema in Alexandria, Virginia, rejected the Justice Department's request to force a divestiture of AdX, Google's marketplace for buying and selling display ads on the open web.

Instead, the judge accepted what her order calls "most of the parties' proposed behavioral remedies, as modified by this Court." The details of those remedies sit in a memorandum opinion that remains under seal for now.

The outcome is a major win for Google and a significant setback for US antitrust enforcers. According to Reuters, it is the third time in recent years that the government has tried to break up a Big Tech company and lost.

What the judge actually ordered

The public order is short, and it is worth being precise about what it does and does not say.

Brinkema rejected all three structural remedies the government and the states had sought:

1. Divestiture of AdX, Google's ad exchange.
2. Open-sourcing the final auction logic in DFP, Google's publisher ad server.
3. A contingent divestiture of the rest of DFP if competition did not recover.

She accepted most of the behavioral remedies proposed by the two sides, with modifications. The order does not list which ones survived or how they were changed. That information is in the sealed opinion.

The opinion is sealed for 14 days so the parties can request redactions of confidential business information. Reuters reports that Brinkema will release the detailed ruling once that window closes. The parties also have 30 days to file a single jointly proposed final judgment, with any provisions they still disagree on shown in both versions.

Key takeaway: Google keeps both AdX and its DFP ad server. It will have to change how they operate, but exactly how, and for how long, will not be public until the sealed opinion and a proposed final judgment are filed over the next month.

How we got here

The Department of Justice and a coalition of states sued Google in January 2023, accusing it of monopolizing the technology that connects websites selling ad space with advertisers buying it.

After a liability trial in 2024, Brinkema ruled in April 2025 that Google held illegal monopolies in two markets: publisher ad servers, where DFP dominates, and ad exchanges, where AdX sits. She also found that Google unlawfully tied the two products together, locking publishers who used its ad server into using its exchange.

The judge wrote at the time that Google's conduct "substantially harmed Google's publisher customers, the competitive process, and, ultimately, consumers of information on the open web."

A separate remedies trial followed in September 2025. The DOJ argued that Google could not be trusted to run AdX given its history and that a clean sale was the safer fix. According to AdExchanger, the government told the court a breakup would be a "cleaner, less risky solution." Google countered that a forced sale would be technically difficult and would drag customers through a long, painful transition. One of its filings said distrust "is not a lever to bypass well-settled antitrust principles."

What was on the table

The key detail in Wednesday's order is that it accepted most of the parties' behavioral proposals. The government and Google had put forward overlapping sets of conduct remedies, and the shared ground gives a reasonable preview of what the sealed opinion may contain.

According to AdExchanger, Google had offered to make real-time AdX bids for open-web display ads available to rival ad servers, to retire its Unified Pricing Rules so publishers can set different price floors for different bidders, and to commit not to use "first look" and "last look" advantages, which it says it stopped using years ago. Google also signaled support for integrating AdX with Prebid, the open-source header bidding framework many publishers use to run auctions across multiple exchanges.

The "likely" in that table is an inference, not a finding. The order says the accepted remedies were modified, so even provisions both sides proposed may look different in the final text.

Why no breakup?

The written reasoning is sealed, but Brinkema signaled her thinking during the remedies phase. AdExchanger reports she raised concerns that disrupting AdX or DFP could hurt the small publishers that use DFP for free, that a sale of AdX to another large company could create new complications, and that behavioral fixes could take effect faster than a breakup that would be tied up in years of appeals.

It also matters that AdX is a relatively small part of Alphabet. Reuters cites a Wedbush analysis of court documents showing Google's Ad Manager business made up 4.1% of Google's revenue and 1.5% of its operating profit in 2020. More recent figures were redacted.

The exchange is, however, lucrative per transaction. Reuters notes publishers pay Google a 20% fee to sell ads through AdX auctions that happen in the instant a web page loads.

Reactions: relief, disappointment and a warning

Google welcomed the decision. "We're very pleased the Court rejected the DOJ's proposal to break apart tools that help small businesses reach new customers and grow," said Google executive Lee-Anne Mulholland, according to Reuters.

The DOJ put a positive spin on it, saying on X that it was "pleased that the court ordered substantial relief" and that it is "evaluating appropriate next steps."

Publisher groups were less upbeat. Danielle Coffey, CEO of the News/Media Alliance, said the ruling "takes some positive steps," but added: "without a requirement to sell its advertising exchange, more will be needed to undo over a decade of market concentration and anticompetitive action."

Some ad tech rivals saw an upside in speed. PubMatic, which runs a sell-side platform that competes with AdX, said in a statement quoted by AdExchanger that "the Court's focus on behavioral remedies will likely provide a more expeditious path to address the ongoing competitive harms."

Critics of Big Tech were harsher. "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," said Sacha Haworth of The Tech Oversight Project, according to the New York Post. Industry group CCIA, which counts Google among its members, praised the decision as correctly "narrowly tailored."

What it means for publishers and advertisers

For now, nothing changes on the ground. The order creates no immediate obligations; those will come with the final judgment, and implementation timelines are still unknown.

When the rules do arrive, the practical questions for publishers are straightforward:

• Can I use a rival ad server and still get Google's demand? Real-time AdX bids flowing to competing ad servers would, in theory, weaken the lock-in the court found illegal. Jay Friedman, a former Goodway Group CEO who testified for the DOJ, told AdExchanger he does not think the judge "provided sufficient answer to this question."
• Will pricing rules get more flexible? Ending Unified Pricing Rules would let publishers set different floors for different buyers, a long-standing request.
• Who checks compliance? Behavioral remedies only work if they are monitored. Whether there will be a trustee or technical committee, and what access it gets, is not yet public.

For advertisers, the effects are more indirect. A more competitive exchange market could, over time, mean a larger share of each ad dollar reaching publishers rather than intermediaries. The 2025 liability ruling did not find a monopoly in advertiser-side tools, and whether any of the accepted remedies reach Google's own buying products will only be clear once the opinion is public.

If you negotiate ad tech contracts, the sensible move is to wait for the final judgment text before switching providers, and to build reopeners into new deals tied to that judgment.

Part of a pattern

Brinkema's ruling fits a trend that is now hard to ignore. Judges have repeatedly agreed that Big Tech firms broke the law, then declined to break them up.

In the search case, Judge Amit Mehta rejected the DOJ's bid to force a sale of Chrome, citing rising competition from generative AI companies such as OpenAI. In the Meta case, a Washington judge found the FTC had failed to prove Meta holds a monopoly in a market that has changed dramatically since the case was filed in 2020.

Cases against Amazon and Apple have not yet gone to trial. Reuters notes the ad tech ruling is fueling questions about whether courts are equipped to check Big Tech's power at all.

What happens next

Several clocks are now running:

1. Around mid-September: the 14-day redaction window closes and the detailed opinion should become public, at least in redacted form.
2. Around early October: the parties file their jointly proposed final judgment, 30 days after the order.
3. After that: the court enters a final judgment, which will set implementation dates and any monitoring regime.
4. Appeals: Google said after the April 2025 liability ruling that it would appeal that decision, and an appeal would go to the Fourth Circuit. The DOJ says it is weighing its options.

Outside the US, the European Commission's separate ad tech case, in which it fined Google €2.95 billion in September 2025, is a distinct proceeding. A Virginia court's decision does not bind European regulators.

FAQ

Does Google have to sell AdX?

No. Judge Brinkema rejected the DOJ's request to force a sale of AdX, along with its requests to open-source DFP's auction logic and to potentially divest the rest of DFP later.

What are the behavioral remedies?

The public order says the court accepted most of the parties' proposed behavioral remedies, with modifications. The specifics are in a sealed opinion. Proposals on the table included real-time AdX bids for rival ad servers, ending Unified Pricing Rules and a ban on first look and last look.

When will the full ruling be public?

Reuters reports the detailed ruling will be released after a 14-day window for redactions, which points to around mid-September. A jointly proposed final judgment is due within 30 days of the September 2 order.

Will Google appeal?

Google said in April 2025 that it would appeal the liability ruling that found it held illegal monopolies. It has welcomed the remedies decision. The DOJ says it is evaluating next steps.

Does this affect what ads I see?

Not directly or immediately. The case is about the plumbing that sells display ads on websites. Any effects would show up over time in how much publishers earn and which companies run their ad auctions.

The bottom line

Google has avoided the outcome it feared most: losing AdX. What it gets instead is a set of behavioral rules whose details will not be public for weeks and whose effectiveness will depend on enforcement for years.

For publishers, the next month matters more than the headline. The sealed opinion and the proposed final judgment will show whether these remedies genuinely loosen Google's grip on open-web advertising or simply formalize changes it has already made. For US antitrust enforcers, it is another reminder that winning in court and reshaping a market are two very different things.