Google avoids ad tech breakup: the antitrust ruling, the numbers, the open questions

The details that matter to publishers and advertisers are still partly sealed. The order itself runs two pages. The reasoning sits in a memorandum opinion filed under seal so the parties could request redactions, a process that reporting citing the docket says concludes around 16 September 2026. A joint proposed final judgment is due by 2 October 2026, according to kurums.com's review of the docket.

What is clear is the shape of the remedy: conduct rules, not ownership changes.

What the judge actually ordered

Brinkema's September 2 order adopted most of the parties' proposed behavioral remedies, as modified by the court. The DOJ had asked for three structural fixes: divestiture 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. She rejected all three. The behavioral measures map onto the practices her April 2025 liability ruling had already documented.

That ruling found Google illegally monopolized two markets under Sections 1 and 2 of the Sherman Act: the publisher ad server market, where it held roughly 91% of worldwide share as measured by impressions served, and the open-web display ad exchange market, where AdX charged a consistent 20% take rate for over a decade without competitive pressure to reduce it. She also found Google illegally tied DoubleClick for Publishers and AdX together.

Four obligations appear in public reporting on the order:

• Real-time bid transparency. Google must make real-time bid amounts for open-web display ads sold through AdX available to competing ad servers.
• End of Unified Pricing Rules. Google must deprecate the 2019 rules that required publishers to apply the same price floor to every bidder, restoring the ability to set different floors for different buyers.
• No first look, no last look. Google is barred from giving AdX priority access to impressions before rival exchanges can bid, and from letting AdX see the highest rival bid before submitting its own offer.
• Interoperability. The court leaned on measures both sides had floated, including closer integration with independent auction technology such as Prebid, rather than mandating a sale of any Google asset.

According to Digital Applied's review of the docket, the parties proposed sharply different monitoring windows: Google floated six years, the government sought ten. The court's chosen duration remains under seal pending the October 2 filing.

The money, which is small

AdX is a minor line item for Alphabet. Google's ad tech business brought in roughly $30 billion last year, about 8% of Alphabet's total revenue. That revenue has declined for 16 consecutive quarters, with analysts estimating it accounts for less than 1% of the company's profit, according to explainx.ai's summary of the financials. Ad Manager 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 cited by Reuters. More recent figures were redacted from court documents.

Google shares pared gains slightly after the ruling and were up 0.6%, Reuters reported.

So the financial stakes of the divestiture fight were never existential for Google. The competitive stakes were a different question, which is why the structural remedy mattered to the DOJ and to publishers.

Why the judge declined the breakup

Brinkema found that breakup risk and delay outweighed the benefit of a forced sale. She was sceptical a qualified buyer for AdX could be found without years of added litigation, according to kurums.com's account of the reasoning. Reporting on the closing arguments also flagged that she said time was somewhat of the essence given how fast AI is reshaping digital advertising, suggesting a lengthy divestiture process could be outdated before it finished.

Google argued a forced sale would be technically difficult and result in a long and painful transition that would hurt customers. It also countered that breaking up a system handling 55 million ad requests per second would be technically unworkable and economically harmful to the small publishers that use DFP at no charge. The company proposed behavioral relief instead: real-time bid sharing, unified pricing rule removal, and compliance monitoring for six years.

Google framed the outcome as a win. Lee-Anne Mulholland, the company's vice president for regulatory affairs, said it 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 that the court ordered substantial relief" and that it is "one step closer to restoring competition and bringing relief for the American people in online advertising markets," adding that it is evaluating appropriate next steps.

That is not a settled outcome. The DOJ's language leaves the door open to further action, and the sealed opinion has not yet been reconciled with the public order.

The pattern matters more than the case

This is the third consecutive time a US judge has rejected a request from antitrust enforcers to break up a Big Tech company, Reuters noted. A federal judge in Washington last year rejected the FTC's attempt to force Meta to sell Instagram and WhatsApp, saying the agency failed to prove Meta holds a monopoly in a social media market that had shifted since the case was brought in 2020; the FTC has appealed. Another Washington judge who had ruled Google holds an illegal search monopoly declined to order a Chrome sale, citing rising competition from generative AI companies such as OpenAI's ChatGPT.

The ad tech ruling also mirrors the outcome one year earlier in that separate Google search case before Judge Amit Mehta in the District of Columbia, where the DOJ's Chrome request was rejected in September 2025 in favour of data-sharing and choice remedies. That case remains on appeal, with Google and the DOJ, joined by 38 state attorneys general, each challenging different parts of Mehta's order.

Two rulings, two consecutive Septembers, the same defendant, two different monopolization cases, and no structural remedy in either. Critics of the search-case remedies argued that behavioural rules without structural change simply move the compliance burden onto Google's own reporting and good-faith adherence, without removing the underlying incentive or capability to repeat similar conduct in a modified form. This ruling extends that critique to a second, independent case.

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 question the order does not answer

What remains unchanged is the infrastructure that produced the practices. 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.

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: "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, but whether it does will be determined in practice, not in the courtroom.

The practical test is straightforward. If publishers can now set different price floors for different buyers, and rival ad servers can see AdX bids in real time, the advantage that made DFP and AdX mutually reinforcing should weaken. If compliance is monitored for six years and the underlying ownership does not change, the incentive to find a modified version of the same conduct does not disappear. The unsealed opinion, due around 16 September, and the joint final judgment due by 2 October, are where the enforceable detail will emerge.

Until then, the headline is accurate but incomplete: Google avoided a breakup it was never likely to face on these facts, and won a conduct regime whose strength depends entirely on how it is policed.