Opera has filed a formal competition complaint against Microsoft in Brazil. The company accuses Microsoft of using deceptive design practices to steer users toward the Edge browser and Bing search engine. According to the complaint, Microsoft often ignores user preferences, blocks preinstallation opportunities for rival browsers, and displays intrusive messages that discourage switching away from its default services.
This filing is part of Opera’s broader effort to challenge what it considers anti-competitive behavior by Microsoft in multiple global markets. The company argues that Microsoft’s design decisions in the Windows operating system interfere with consumer freedom and give Edge an unfair advantage. In a public statement, Opera’s general counsel, Aaron McParlan, said the company is seeking regulatory intervention to restore fair competition and reduce Microsoft’s control over browser selection.
“Microsoft thwarts browser competition on Windows at every turn,” McParlan said. “First, browsers like Opera are excluded from key preinstallation opportunities. Then, Microsoft makes it difficult for users to download and adopt other browsers.” The complaint claims these actions not only limit user autonomy but also violate fundamental principles that support fair access and interoperability.
Allegations Focus on Default Settings and User Interference
At the heart of the complaint are specific accusations concerning how Microsoft handles browser defaults and link behavior within the Windows environment. Opera claims that Microsoft overrides user choices by forcing certain links to open in Edge. This includes links from Outlook, Teams, and Windows search results. The complaint also mentions the Windows Widgets panel, which opens links in Edge regardless of the user’s preferred browser.
Opera further accuses Microsoft of using pop-up messages and warnings to prevent users from downloading other browsers. These alerts appear when users are actively trying to install competing software using Edge. The complaint describes these prompts as aggressive and confusing, designed to create hesitation and benefit Microsoft’s products.
Another issue raised in the filing involves Windows “S Mode,” a restricted version of the operating system that only allows installations from the Microsoft Store. Opera argues that Microsoft offers financial incentives to PC manufacturers to ship devices with this mode enabled. The result is that users cannot install third-party browsers unless they fully opt out of S Mode.
Brazil Becomes the Focal Point in Global Dispute
Opera selected Brazil as the site of this complaint due to its strong user base in the country. According to McParlan, Opera is the third most widely used browser in Brazil, which makes the market significant to the company’s long-term growth. He stated that this case presents an opportunity for Brazil to lead on a global issue affecting digital freedom.
Although the case is currently under review by Brazil’s competition authority, the implications could extend far beyond the country’s borders. Opera has already challenged Microsoft in Europe by appealing a decision from the European Commission that did not classify Edge as a gatekeeping service under the Digital Markets Act. While Microsoft has made adjustments to Windows in European Union markets, Opera believes those changes fall short of what is needed to ensure open competition.
Opera’s complaint outlines several proposed remedies. These include allowing computer manufacturers to preload third-party browsers, eliminating interface designs that nudge users toward Edge, and stopping the behavior that overrides default browser settings. Opera insists that these changes are essential for giving consumers meaningful control over their web browsing experience.
Microsoft’s Browser Strategy Faces Renewed Scrutiny
This is not the first time Microsoft has faced backlash over its browser tactics. In 2007, Opera filed an antitrust complaint in the European Union. That case led to the creation of a browser selection screen in Windows, giving users the option to choose among different browsers. Microsoft was later fined 730 million dollars in 2013 for failing to include the browser ballot in Windows 7 Service Pack 1.
In more recent years, Microsoft drew criticism for a campaign that imitated Google’s interface within Bing search results. Critics said this effort was intended to mislead users into thinking they were using Google. Microsoft eventually discontinued the feature after public attention intensified. These incidents, along with Opera’s latest filing, have brought renewed attention to how Microsoft promotes its products within the Windows platform.
Microsoft has not yet issued a public response to the new complaint. The company has made some concessions in response to regulatory pressure, especially within the European Union. It remains unclear whether those adjustments will be enough to prevent additional legal action or satisfy competing browser developers. For now, Opera’s move in Brazil adds another layer to the global conversation about digital platforms and user choice in the software ecosystem.