TL;DR
- The full US ad tech antitrust opinion is public: Judge Brinkema rejected a breakup and imposed behavioural remedies, reported by Search Engine Roundtable on 17 September 2026.
- Google must let Prebid and the DFP ad server pull real-time bids from AdX, stop discriminatory bidding, share data, and accept routing restrictions on AdWords; DV360 was left untouched.
- A paid independent monitor oversees compliance for six years, reporting quarterly with a Google response window before the court can act.
- Timeline: 12 months to open AdX to rival ad servers, 12 to 15 months to connect AdX and DFP to Prebid, with the whole judgment running within 15 months.
- It covers only open web display, which fell from 40% to 11% of AdWords impressions between 2019 and 2025, and applies everywhere Google's ad tech operates, not just the US.
The full court opinion in the US ad tech antitrust case is now public, and it spells out exactly what Google must do: open its ad exchange to rival ad servers, share data, stop favouring its own tools, and submit to a paid independent monitor for six years. Judge Leonie Brinkema rejected a breakup and imposed behavioural remedies instead. Search Engine Roundtable reported the memo on 17 September 2026, linking the court filing.
We covered the decision itself earlier this month, when the judge rejected the forced sale of AdX and accepted behavioural remedies in principle. What is new now is the detail: the full opinion names the specific operational changes, the oversight structure, and the timeline. This is the difference between knowing a law passed and reading the regulations that implement it.
What the remedies actually require
The judge grouped the remedies into three areas: forcing Google to open up and share data with rivals, stopping Google from favouring its own tools, and stopping Google's ad-buying arm from gaming auctions for its own ends. The concrete requirements below sit under those headings.
| Remedy | What it means |
|---|---|
| No divestiture | Google keeps AdX and its publisher ad server. The judge called a forced sale "neither realistic nor needed". |
| Mandatory integration | Google must let Prebid, the open-source auction tool many publishers already run, pull real-time bids from AdX. DFP gets the same treatment. |
| Ban on discriminatory bidding | An injunction stops Google favouring its own products over competitors in the auction. |
| Data-sharing | Google must enact basic data-sharing to level the field for rivals. |
| AdWords routing restrictions | Nondiscrimination and routing rules on the buy side, because AdWords was found to be part of how Google steered money to AdX. |
| Monitor and Technical Committee | A third-party monitor Google pays for oversees compliance for six years, with the court able to extend. |
The two remedies the industry actually wanted
The change ad tech executives said would matter is the mandatory integration. Google must let Prebid, and the DFP ad server, pull live bids out of AdX, so publishers can finally make Google's exchange compete for their inventory through the same neutral pipe every other seller uses. In principle AdX starts losing some auctions it used to win by default, and publishers earn more because Google can no longer set terms without a real fight for the business.
That is the theory. Not everyone believes it will play out. Privacy expert Alan Chapell argued that Google is, in his words, "brilliant at playing the behavioural remedies game": it can surround access to AdX demand with conditions and audits, write narrow promises that ban yesterday's tactics while it invents new ones, and lean on opaque privacy technology so publishers cannot really audit what happens to their data. An anonymous ad tech specialist who examined the proposals put it more bluntly: the commitments are written to satisfy narrow legal promises, not to guarantee any change in what publishers earn, and he expects few publishers to change anything.
The buy side mostly survived
Google argued its ad-buying tools, AdWords and DV360, should be untouched because the original ruling never found a monopoly in buying tools. The judge partly agreed. She zeroed in on AdWords, because it was found to be part of the mechanism: Google steered AdWords advertisers to bid into AdX specifically, and made publishers run AdX and DFP together to get a shot at that AdWords money. So AdWords gets nondiscrimination and routing restrictions. DV360 was left alone, because the government never put forward evidence that it worked the same way.
This is the part that leaves the remedies open to the charge that they regulate auction access while leaving the buy-side integration intact. The court also flagged a workaround worth watching: Google already has a tool, Google Partner Bidding or gBid Direct, that lets its buying arm bid directly into a publisher's auction for in-app inventory, skipping the exchange. It does not do this for open web display yet, but the court treated the possibility as a real risk.
Two details that blunt the impact
Two facts in the opinion matter as much as the remedies themselves. The first is timing. Google has 12 months to open AdX to rival ad servers and 12 to 15 months to connect AdX and DFP to Prebid, and the judge said the whole judgment should be running within 15 months. That is over a year before any of this shows up in what publishers actually earn.
The second is enforcement speed. There is an independent monitor, but the judge sided with Google on how it works: it reports every three months rather than whenever something goes wrong, and Google gets over a month to respond and fix an issue before anyone can take it to the judge. Executives had warned that if breaking a rule takes eight or nine months to punish, the damage is done before the remedy bites, and this is the slower, more Google-friendly version of the oversight that was on the table.
The remedies target a shrinking market
The most important limit is scope. All of this applies only to open web display ads, the traditional banner and display inventory on websites. It does nothing for the fast-growing formats: streaming TV ads, in-app ads, and retail media. Google's own numbers make the point, with the share of AdWords ad impressions going to traditional display falling from over 40% to 11% between 2019 and 2025. The fix targets the slice of the market that shrinks every year, while the growth has moved elsewhere.
The oversight also applies everywhere Google's ad tech operates rather than in the United States alone, so the behavioural rules reach global publishers and advertisers even though the case is American.
What this means for advertisers, including in Thailand
For most advertisers, and for almost all Thai advertisers, the honest near-term answer is that little changes in how you run campaigns. This is a publisher-and-ad-tech ruling about the open web display supply chain, not a change to how you build a Search or Shopping campaign. Nobody needs to alter an account this month because of it.
What is worth understanding is the direction. If the remedies work as intended, open web display auctions become a little more competitive over the next 12 to 15 months, which could mean modest shifts in display inventory pricing and where impressions clear. Thai advertisers buying open web display, directly or through Google Ads, may see second-order effects on cost and availability, but not soon and not dramatically, and the ruling does not touch the streaming, in-app, and retail media formats that are taking the growth. The practical stance is to keep measuring outcomes in your own account rather than reacting to an antitrust headline that will take more than a year to reach the auction.
What the ruling did not settle
Several things remain open. The opinion did not resolve whether the remedies will actually move money to publishers, and the people closest to it are openly sceptical. It did not address the growth formats at all. It left DV360 untouched, which critics say leaves the buy-side integration that drove the conduct largely intact. And it set an oversight design, quarterly reporting with a Google response window, that its own critics say is too slow to punish a breach before the harm lands. Whether behavioural remedies can hold a company the court itself said it did not fully trust is the question the next six years will answer.
Frequently asked questions
Is Google being broken up over the ad tech case?
No. Judge Brinkema rejected a forced divestiture, calling it "neither realistic nor needed", and imposed behavioural remedies instead. Google keeps its AdX exchange and its publisher ad server, under a six-year oversight regime.
What is the most significant remedy?
Mandatory integration: Google must let the open-source tool Prebid, and the DFP ad server, pull real-time bids from AdX, so publishers can make Google's exchange compete through a neutral pipe. Ad tech executives said this is the change that could matter most, though some doubt it will move much money in practice.
When do the remedies take effect?
Google has 12 months to open AdX to rival ad servers and 12 to 15 months to connect AdX and DFP to Prebid, with the judge expecting the whole judgment running within 15 months. Effects on what publishers earn are more than a year away.
Does this change how I run Google Ads campaigns?
Not directly. This is a ruling about the open web display supply chain, not about Search or Shopping campaign mechanics. The main buy-side effect is AdWords routing and nondiscrimination rules; DV360 was left untouched. Most advertisers will not change anything this month.
Does it apply outside the United States?
Yes. The behavioural remedies apply everywhere Google's ad tech operates rather than in the US alone, so global publishers and advertisers fall under the rules even though the case is American. It only covers open web display, not streaming, in-app, or retail media.
The bottom line
The opinion turns a headline verdict into a specific to-do list for Google: open AdX to Prebid and rival ad servers, stop discriminatory bidding, share data, accept routing limits on AdWords, and live under a paid monitor for six years. It is real, it is global, and it is slow, taking up to 15 months to arrive and covering only the shrinking open web display market. For advertisers the near-term change is minimal; the story to watch is whether behavioural remedies can do what a breakup was meant to, or whether, as the sceptics expect, publishers get tougher-looking rules and little else.
