How Mozilla Bypassed Windows 11 Restrictions to Make Firefox the Default Browser

Last month we reported that Microsoft made it harder to switch the default browser in Windows 11, drawing criticism from competitors such as Google and Mozilla.

To simplify the process, Mozilla discovered an unconventional method that lets Windows users change the default browser more easily.

In Windows 10, users can change the default browser with a few steps in the system settings. In the upcoming Windows 11, users must configure each file type (HTM, HTML, SHTML, XHT, XHTML, FTP, HTTP, HTTPS, WEBP, PDF, SVG, etc.) individually, losing the single‑switch control.

Mozilla has implemented a solution where clicking “Set as Default Browser” inside Firefox automatically redirects to the Windows settings and completes the change without further user interaction. This works on both Windows 10 and Windows 11.

The technique involved reverse‑engineering Microsoft’s method of setting Edge as the default browser, allowing Firefox to bypass Microsoft’s anti‑hijack protection and perform the necessary registry changes in the background.

Previously, after clicking “Set Default,” Firefox would open the Windows settings page, requiring the user to manually select Firefox under the “Web browser” option and confirm the change. The new approach completes the entire process silently.

Mozilla’s spokesperson stated that users should be able to set defaults easily and that operating systems should provide official support for changing default applications, enabling users to set their preferred apps without obstacles.

This precedent may encourage developers of Chrome, Brave, Vivaldi, and other browsers to analyze and adopt similar functionality in their products.