Firefox 91: Enhanced Cookie Clearing, Windows SSO and prioritization of HTTPS


Mozilla has released version 91 of the Firefox browser for Windows, macOS and Linux. The ESR variant (Extended Support Release) is also available with the same version number. In addition to innovations such as enhanced cookie clearing, single sign-on (SSO) with the Windows account for several Microsoft services and the prioritization of HTTPS connections, Mozilla closes various security gaps with the new version.

Enhanced Cookie Protection is based on “Total Cookie Protection” and is intended to make it easier for users to see which websites are storing information on their computers. In addition, the thorough deletion of cookies should be made easier. If Firefox is instructed to forget a website, all cookies and supercookies as well as other data stored in the website’s cookie jar are automatically deleted. This should delete all traces of a website in the browser, including third-party cookies.

Firefox 91 will support Windows SSO in the future. Users can log into their Microsoft, business and school accounts with the Windows 10 access data. The function can be switched on in the settings for “Data protection and security”. To activate it, it is sufficient to check the box next to “Allow Windows single sign-on for Microsoft, business and school accounts”.

Firefox 91 also prioritizes encrypted connections to websites over HTTPS. Only if the websites do not support HTTPS is there a fallback to an insecure HTTP connection.

A function for printing web pages is available again in a simplified and print-friendly view without having to print out disruptive elements such as advertising banners. The reading view can be activated using an icon in the address bar and a printout of the website can then be started using the print function.

All Changes are listed in the release notes. Additionally Firefox addresses 91 different security vulnerabilities that Mozilla lists on its own website.

Users who have installed the Firefox browser will automatically receive the new version in the next few days. Otherwise, the installation can be started manually via “Help> Via Firefox> Update to version 91.0”. Additionally Version 91 for Windows, macOS and Linux is available for download on the Mozilla website.


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