Firefox 91 arrives with HTTPS-First, improvements for TCP, print mode, file download and more

The new version of Firefox 91 has already been released which is classified as a long-term support branch (ESR) with updates posted throughout the year. In addition, along with this new version, the new update of the previous branch ESR 78.13.0 has also been released

In this new version of the browser that is presented plus innovations and bug fixes, firefox 91 has fixed 19 vulnerabilities, of which 16 are marked as dangerous, of which 10 of them are caused by memory problems such as buffer overflows and access to already freed memory areas.

Main new features of Firefox 91

In this new version of Firefox 91, the policy HTTPS-First is enabled by default, similar to the "HTTPS only" option previously available in the configuration. When trying to open a page without encryption via HTTP in private mode, the browser will first try to access the site via HTTPS and if the attempt fails, it will automatically access the site without encryption.

Another important change is the TCP method capabilities enhancements (Full Cookie Protection), It is activated in private browsing mode and when strict blocking spam (strict) mode is selected. In the new version, the method of removing cookies has been changed to exclude data leaks hidden, and users are now informed about the sites that store information locally.

Also in Firefox 91 the change in the logic of saving open files after uploading, as after downloading in external applications they are now saved in the normal "Downloads" directory, instead of a temporary directory.

Also the print mode of a shortened version of the page is returned, which resembles the view in reader mode, in which only the meaningful text of the page is displayed, and all related controls, banners, menus, navigation bars and other non-content related parts of the page are hidden. The mode is activated by activating the Reader View before printing. LSupport for this mode was discontinued in the Firefox 81 release, after switching to the new preview interface before printing.

While for the «Switch to tab» mode, which allows you to switch to a tab from the list of recommendations in the address bar, now covers pages in private browsing window.

Finally in the version of Firefox for Windows have added support for single sign-on technology (SSO), which allows you to connect to sites using credentials from the Windows 10 environment.

How to install or update the new version of Firefox on Linux?

Firefox users who have not disabled automatic updates will receive the update automatically. Those who don't want to wait for that to happen can select Menu> Help> About Firefox after the official launch to initiate a manual update of the web browser.

The screen that opens displays the currently installed version of the web browser and runs a check for updates, provided the functionality is enabled.

Another option to update, is yes you are a user of Ubuntu, Linux Mint or some other derivative of Ubuntu, You can install or update to this new version with the help of the browser's PPA.

This can be added to the system by opening a terminal and executing the following command in it:

sudo add-apt-repository ppa:ubuntu-mozilla-security/ppa -y 
sudo apt-get update
sudo apt install firefox

In the case of Arch Linux users and derivatives, just run in a terminal:

sudo pacman -Syu

Or to install with:

sudo pacman -S firefox

Finally for those who prefer to use Snap packages, They will be able to install the new version as soon as it is released in the Snap repositories.

But they can get the package directly from Mozilla's FTP. With the help of a terminal by typing the following command:


And to install the package we just type:

sudo snap install firefox-91.0.snap

Finally, you can get the browser with the latest installation method that was added "Flatpak". To do this, they must have support for this type of package.

Installation is done by typing:

flatpak install flathub org.mozilla.firefox

For, all other Linux distributions can download the binary packages from the following link.

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  1.   M said

    It is not updated on Linux Mint.