Mozilla-funded report says Windows pushes users toward Edge

A Mozilla-commissioned report accuses Microsoft of using Windows, Bing and Copilot interface choices to steer people toward Edge, with no financial transaction involved and no new product launch. The claim matters for browser makers and regulators because it frames Microsoft’s AI and OS defaults as distribution leverage, not just product marketing.

The report, titled Over the Edge 2.0, was published this week and examines Microsoft’s behavior in Germany, used as a proxy for the European Economic Area, as well as India, the UK and the US. Its central finding is that Microsoft interferes with users who try to download, set as default, or continue using browsers other than Edge.

Examples cited in the report include Bing showing a banner that tells users they already have what they need when they search for rival browsers, Edge being pinned to the Windows taskbar by default, and wording that the researchers say can lead users into making Edge their default browser. The report also says Microsoft treats markets differently: some of the prompts and overrides found in the UK, US and India were not found in the EEA.

Copilot is part of the complaint. According to the report, Microsoft’s AI assistant opens links without respecting the browser a user has chosen as default. The researchers also found that Copilot data-sharing settings were preselected to on in the US and India. Microsoft has been pushing Copilot across Windows and Microsoft 365, so browser routing through the assistant is not a small implementation detail for competitors that depend on user choice inside Windows.

The EEA comparison is the most useful part of the report for regulators. Mozilla’s researchers say the Bing banner does not appear there, Edge banners are not inserted on the Chrome download page, and Windows Search does not automatically route through Edge instead of the default browser. That suggests Microsoft can change these behaviors when legal pressure requires it.

The Browser Choice Alliance endorsed the report and said Microsoft uses manipulative patterns on Windows 11 at global scale to limit browser choice and tilt competition toward Edge. Vivaldi also criticized Microsoft. Bruce Lawson, Vivaldi’s technical communications officer, told The Register that the findings support complaints browser companies have made to regulators, and argued that Microsoft relies on its control of Windows rather than competing on browser quality. He also called for regulators in the UK, Australia and Japan to act.

Microsoft did not respond to The Register’s request for comment. The company also does not publish official Edge market share figures, leaving outside measurements as the available benchmark.

Statcounter, which says its tracking code runs on more than one million websites and records billions of page views, puts Edge at a little over 10% browser share, down from 13% in June 2025. Firefox, Mozilla’s browser, rose to 6.44% from 5.84% a year earlier, according to the same data.

Mozilla disputed the idea that the alleged tactics have failed. A Mozilla spokesperson told The Register that the relevant comparison is Edge’s share on Windows, where the report’s authors found Edge was the only browser to gain share over the past two years. The researchers said they hypothesize that the patterns they identified contributed to that growth. That is still a hypothesis, not proof of causation, and the public data cited does not settle the question.

This story draws on original reporting from The Register.