The General Court today dismissed Opera Norway's challenge to the European Commission's refusal to designate Microsoft as a gatekeeper for Edge, leaving the browser outside the obligation that would have placed a choice screen in front of Windows users across the European Union.

Judgment in Case T-357/24 was delivered in open court in Luxembourg on 2 September 2026 by the Eighth Chamber sitting with five judges. The panel comprised M. van der Woude as President, G. De Baere, D. Petrlik as Rapporteur, K. Kecsmar and S. Kingston. The action was dismissed in its entirety, and Opera Norway AS was ordered to bear its own costs and to pay those incurred by the Commission and by Microsoft Corp., which intervened in support of the Commission. English was the language of the case.

The dispute concerned a decision that is now more than two and a half years old. On 12 February 2024 the Commission closed the market investigation covering three Microsoft services and concluded that none of them crossed the threshold that triggers regulatory duties. Article 1 of that decision states that Microsoft is not designated as a gatekeeper in relation to Bing, Edge and Microsoft Advertising. Opera challenged only the Edge portion.

What the Commission decided and why Opera sued

Microsoft notified the Commission on 3 July 2023 that it met the quantitative thresholds in Article 3(2) of the Digital Markets Act for the Windows PC operating system, Bing, Edge and Microsoft Advertising. Alongside that notification it filed rebuttal arguments under Article 3(5), contending that Bing, Edge and Microsoft Advertising did not in fact satisfy the conditions in Article 3(1) because of the circumstances in which they operated.

On 5 September 2023 the Commission designated Microsoft as a gatekeeper for Windows PC OS by Decision C(2023) 6106 final. The same day, by Decision C(2023) 6078 final, it accepted that Microsoft had raised arguments substantiated enough to manifestly call the presumptions into question and opened a market investigation under Article 16(1) and Article 17(3). The three case numbers were DMA.100015 for online search engines, DMA.100028 for web browsers and DMA.100034 for online advertising services.

The stake for Opera was specific rather than abstract. Under the second subparagraph of Article 6(3), a gatekeeper must let end users change the default settings that steer them toward the gatekeeper's own products, and must prompt users of a designated browser, on first use, to pick a default from a list of the main available providers. Article 3(10) sets a six-month compliance deadline once a service is listed. Had Edge been designated, Microsoft would have been required to show that list to Edge users on Windows PC OS.

Whether Opera would have appeared on it was contested but not seriously in doubt. The applicant produced StatCounter data showing that between June 2023 and June 2024 Opera was the fifth most significant browser on personal computers in the region defined as Europe and sixth across all devices by share of web page views. Data covering January 2023 to March 2025, reproduced in Microsoft's statement in intervention, kept Opera in fifth place on personal computers throughout. Microsoft itself described Opera as a material web browser and grouped it with Chrome and Firefox among the most popular Windows-compatible browsers.

Microsoft's own argument supplied the confirmation. Contending that a choice screen would mainly help Google, the intervener wrote that "all material web browsers other than Edge have Google Search set as the default search engine[, so that] if a user chose, e.g., Opera ..., all searches made in [that web browser] would show results from Google Search". The court read that as an acknowledgement that Opera might have appeared on the screen. Annexes to the application also showed Opera listed on the Chrome and Safari choice screens in March and May 2024 in every member state.

The usage numbers the court accepted

The Commission's first ground rested on scale. According to the contested decision, Edge accounted for 5.8% of web page views across all device types in Europe in December 2022. Chrome represented 59% of those views and Safari 22%. Over the 2020 to 2022 period the figures were 60% for Chrome, 20% for Safari, 6.4% for Firefox and 3.9% for Edge.

Opera argued this was market share analysis by another name, prohibited by recital 23 of the regulation, which excludes justifications on economic grounds that seek to enter into market definition. The court rejected the characterisation. Defining a relevant market requires determining a product market and a geographical market, and nothing in the decision showed the Commission had done either. It had not expressed any view on whether markets should be defined by device type or by region. A footnote referring to StatCounter data on web browser market share reflected StatCounter's own labelling, not a Commission finding.

The court also confirmed that comparison between services is permitted. Recital 23 lists the overall scale of activities of the service concerned among the elements that relate directly to the quantitative criteria, and the list is not exhaustive. An argument that a service is small relative to rivals rebuts the presumption in Article 3(2)(b) concretely and specifically, because it addresses importance as a gateway rather than efficiency or market definition.

On the question of raw user numbers, recital 56 of the contested decision recorded that Edge had a high number of end users. The Commission concluded nonetheless that "irrespective of the high number of end users, Edge's scale of usage compared to other web browsers [was] significantly lower". The court held that nothing in Article 3(5) or recital 23 makes end user counts predominant over other considerations.

A device-specific reading fared no better. Opera argued that Edge mattered on personal computers even if it did not matter overall, and that personal computer users form a distinct category. Article 2(2)(g) defines the service category simply as web browsers, without distinguishing by device or operating system, consistent with the technology-neutral definition sought in recital 14. Assessment must cover the overall scale of activities. On Windows PC OS machines, Edge accounted for between 20% and 30% of all browser minutes from September 2022 to August 2023, against 50% to 60% for Chrome and 10% to 20% for Firefox.

That last comparison did double duty. Opera contended that Edge was the indispensable route for downloading a rival browser on a new Windows machine, since the first download always went through Edge. The court accepted the mechanism and rejected the conclusion: Chrome and Firefox had both overcome it.

Growth arguments were also dismissed. Opera cited a rise in Edge's share on personal computers in Europe from zero at launch in 2015 to roughly 14% in 2024. Microsoft explained, without contradiction, that Edge had replaced Internet Explorer and that the increase came overwhelmingly at the expense of that predecessor rather than at the expense of rivals.

The second ground was more novel, and it is the part of the ruling likely to be cited elsewhere. Recital 59 of the contested decision found that Microsoft does not control the relevant architecture of Edge because the browser has no engine of its own and depends on Blink, the rendering engine managed by the Chromium project. Content rendering on Edge is therefore predicated on conforming with Blink rather than on an autonomous choice by Microsoft.

Opera attacked this on two fronts: that the reasoning was too thin to satisfy Article 296 TFEU and Article 41 of the Charter, and that it was wrong on the merits because Blink is open source and Microsoft could modify it.

On reasoning, the court conceded the recital is succinct but read it against recital 43 of the regulation, which identifies the browser engine as responsible for speed, reliability and web compatibility, and against recital 47 of the decision, which summarised Microsoft's account of why it abandoned its own engine. That account was blunt: website owners had stopped ensuring compatibility, extension developers had stopped building for it, sites performed poorly, and users left for Chrome and Safari. The court added a third element, noting that Opera itself builds on Blink and is necessarily aware of what dependency on a third-party engine implies.

On the merits, the applicant identified three routes by which Microsoft could in principle diverge from Blink: local modifications before compiling Edge, upstream contributions to Chromium, and real-time manipulation of website code through something like a built-in ad blocker. The court found the first and third undercut by incentive. Microsoft switched to Blink precisely to fix rendering quality, so changes degrading speed, reliability or compatibility would reproduce the problem it had solved.

Examples of divergence offered in the application turned out, on Microsoft's uncontested clarification, to be modifications to the software built around the engine rather than to the engine itself. Interface, address bar, settings menus, password storage and security policy all sit in that surrounding layer. One exception survived: the Storage Access application programming interface, through which Edge lets websites seek user consent on privacy matters such as blocking third-party cookies. The court accepted that this affects how business users reach end users, but held that Opera had not explained how it allowed Microsoft to influence a substantial part of business users to its own advantage.

The upstream route failed on governance. Microsoft can propose changes to Blink in the same way as anyone else, and each proposal must be reviewed and approved by a Chromium administrator. That, the court held, is not autonomy.

Ecosystem advantages weighed and discounted

The third ground addressed the distribution machinery. It was common ground that Edge is pre-installed on Windows, that Microsoft has offered incentives to hardware manufacturers to set it as default, that it is pinned to the taskbar, that Windows and other Microsoft applications open websites in it by default, that users attempting to download a rival browser from Edge were shown a message discouraging the step, and that Bing Chat access was given preferentially to Edge users.

The court did not dispute any of that. It held instead that what matters is the benefit an ecosystem confers, not its existence, and that the benefit here was insufficient. Despite every one of those practices, Edge's usage on Windows machines stayed significantly below Chrome's and close to Firefox's.

The lever argument received the same treatment. Between 70% and 80% of average monthly Bing search queries are made through Edge, and between 80% and 90% of Bing searches happen on Windows devices. Those figures show Bing depends on Edge. They do not show Edge is important, because Bing's own scale of usage in the European Union sat between 3% and 5% across all device types, and remained very limited against Google Search from 2020 to 2022. A lever that has not moved anything is, on this reasoning, not much of a lever.

The court added a forward-looking point. Microsoft's designation for Windows PC OS already obliges it under Article 6(3) to let users uninstall applications and change defaults easily, which weakens further its ability to drive Edge usage through the operating system. Opera questioned whether Microsoft would comply; the court noted that Articles 30 and 31 provide for fines and periodic penalty payments, giving gatekeepers an incentive to do so.

Independent research has taken a less sanguine view of how those defaults behave in practice. A Mozilla-published study documented interface patterns that override browser choice across Windows 10 and Windows 11, extending into Copilot and the Windows Backup migration tool. That work postdates the contested decision and formed no part of the file before the court.

Standing, and the market investigation participation problem

Before reaching any of this the court had to dispose of the Commission's plea of inadmissibility, lodged on 1 October 2024 and reserved for judgment on 14 January 2025. The Commission argued Opera was a reluctant participant that initially refused to answer the request for information sent to competitors on 20 September 2023, replied late and incompletely on 12 October 2023, and had not even claimed at the time that Edge was an important gateway.

The court agreed the replies were succinct and thin. It held them sufficient anyway, because the regulatory framework gives third parties no participation rights at all unless the Commission chooses to send a request under Article 21 or to interview them under Article 22. Opera answered a request made under Article 21(2), which carries no penalty for silence, rather than a decision under Article 21(3), which does. The Commission could not fault a competitor for failing to volunteer material through a channel the regulation does not provide.

On market position, the court found the non-designation liable to cause a substantial adverse effect. Opera's usage in December 2022 was similar to Edge's, only slightly lower by web page views, and Opera is optimised for Windows PC OS. A choice screen shown to Edge users would have let Opera reach an installed base comparable to its own. The applicant was directly concerned as well, since the decision produced its effects automatically without intermediate rules.

One complaint was ruled inadmissible on procedural grounds. Opera criticised the reliability of StatCounter data for the first time in its observations on Microsoft's statement in intervention, having not raised it in the application. The court rejected it under Article 84(1) of the Rules of Procedure and added that it would have failed anyway: recital 55 shows the Commission cross-checked against other sources, and Opera had declined to criticise StatCounter when questions C.1 and C.2 of the request for information invited exactly that.

What the Commission had to investigate on its own

The fourth part of the plea raised a structural question with implications beyond this case. Opera argued that the Commission should have applied the qualitative factors in Article 3(8), including size, network effects, data-driven advantages, lock-in, switching costs and monetisation potential, when assessing Microsoft's rebuttal.

The court drew a firm line between two designation routes. Article 3(4) and 3(5) govern quantitative designation, where thresholds are met and the burden of rebuttal sits with the notifying company; Article 17(3) applies and the indicative deadline is five months. Article 3(8) governs qualitative designation, where thresholds are not met; Article 17(1) and 17(2) apply and the deadline is twelve months. The 2020 legislative proposal had used the same criteria for both. The final text did not, and the court treated that as a deliberate choice.

That does not leave the Commission passive. The principle of good administration in Article 41 of the Charter requires it to conduct market investigations diligently and impartially, using its own powers to establish relevant facts rather than confining itself to whatever the notifying company submits. It is not obliged to search on its own initiative for everything that might be connected to a case, but it must consider relevant material it has or could reasonably have obtained.

On the record, the court found the Commission had done so. It examined ecosystem integration, put a question to competitors about artificial intelligence advantages in Edge, asked about private browsing, password management, cookie blocking and form auto-fill, and sent separate requests on 20 September 2023 to business users and to other undertakings covering website owners, extension providers, web app providers and developers. Fewer than one third of business users and other participants regarded Edge as important or crucial; one quarter called it relevant; one third called it less relevant or not relevant. Website owners ranked Chrome first, Safari second, and placed Edge and Firefox at a similar level below.

Several of Opera's Article 3(8) arguments failed for a simpler reason. The court repeatedly observed that the applicant asserted relevance without explaining it, and produced no evidence that the Commission held specific material it had ignored. Question F.3 of the request for information had invited any further observations. None were submitted.

Two points the documents leave unresolved

The judgment and the accompanying press release describe the contested measure differently. Paragraph 1 of the judgment calls it Council Implementing Decision C(2024) 806 final; the press release footnote calls it Commission Implementing Decision C(2024) 806 final. The substance, date and case numbers match in both.

The Edge usage figures also appear in two framings that sit awkwardly together. Paragraph 12 presents 3.9% as the 2020 to 2022 average and 5.8% as the December 2022 reading. Paragraph 199 presents 3.9%, 5.6% and 5.8% as readings from three separate data sources. Neither document reconciles them, and the court did not need to, since Firefox exceeded Edge on all three.

Why this matters for advertisers and publishers

The commercial consequence is narrow and durable. Edge remains the only browser operated by a vertically integrated designated gatekeeper that does not have to show a choice screen. Opera made that argument directly and the court rejected it as unexplained, but the asymmetry it describes is now judicially confirmed rather than merely asserted.

For media buyers, the relevant number is not Edge's share but Bing's dependency on it. Microsoft's search advertising business reaches its owned audience largely through the browser, and search advertising growth slowed to 10% in the fourth fiscal quarter as third-party arrangements reshaped the mix. A designation would have inserted a competitor list ahead of the acquisition funnel that feeds Bing and Copilot inventory. That did not happen, and on the two-month and ten-day appeal window it will not happen soon.

The ruling also sharpens what counts as evidence in designation disputes. Reliance on a third-party rendering engine is now an accepted rebuttal factor, which matters for every browser built on Chromium and for any future assessment of services that sit on infrastructure their operators do not control. Publishers reading the same logic will note that the court treated the Storage Access interface, which governs third-party cookie consent prompts, as affecting how business users reach end users while still finding it insufficient to establish gateway status.

The judgment lands in a sequence of decisions trimming the designation perimeter. Three months ago the same chamber annulled Facebook Marketplace's designation while upholding Messenger, and in July Apple's challenge to its App Store and iOS designation was dismissed. Read together, the three rulings suggest the Commission's classification work survives review when it is grounded in service-level evidence and falls when it is not.

Choice screens themselves remain of contested value. Research covered in July found they delivered Firefox roughly six million additional users in the Union while Google Search held near 90% share, with most of the gain flowing to American firms rather than European challengers. Opera has meanwhile reported growth outside the jurisdictions where the screens are mandated, posting 48% combined mobile user growth in the United Kingdom and United States in July 2026.

One geographic detail sits quietly in the file. Opera Norway is established in Oslo, and the browser choice screen obligation described throughout the judgment is framed by reference to the European Union rather than the wider EEA in which its home country sits. The company litigated in Luxembourg over a screen its own domestic market would not have seen.

Timeline

Summary

Who: Opera Norway AS, publisher of the Opera browser and established in Oslo, brought the action against the European Commission. Microsoft Corp. intervened in support of the Commission. The Eighth Chamber of the General Court, sitting with five judges under President M. van der Woude with D. Petrlik as Rapporteur, decided the case.

What: The court dismissed in its entirety an action for annulment of the Commission decision of 12 February 2024 declining to designate Microsoft as a gatekeeper in relation to Edge. It confirmed that Edge is not an important gateway within the meaning of Article 3(1)(b), accepting three grounds: low scale of usage at 5.8% of European web page views in December 2022 against 59% for Chrome and 22% for Safari, dependence on the Blink browser engine, and insufficient benefit from integration into the Windows ecosystem. Opera was found to have standing but lost on the substance and was ordered to pay costs.

When: Judgment delivered on 2 September 2026, following a hearing on 22 October 2025 and an action lodged in 2024 against a decision adopted on 12 February 2024. An appeal limited to points of law may be brought before the Court of Justice within two months and ten days of notification.

Where: The General Court of the European Union in Luxembourg, in Case T-357/24. The underlying usage data covers the region defined as Europe by StatCounter, with the regulatory obligations at issue applying across the European Union.

Why: Designation would have obliged Microsoft, within six months, to present Edge users on Windows PC OS with a browser choice screen listing rival providers under Article 6(3). Opera, ranked fifth on European personal computers, argued the absence of that screen substantially harmed its market position. The court accepted the harm for the purposes of standing but held the Commission entitled to conclude that Edge's usage, its reliance on a third-party rendering engine and the limited effect of Microsoft's promotion practices together rebutted the presumption of gateway status.