Mozilla Firefox is a web browser that can be configured with great granularity, while respecting a user's privacy, unlike Google Chrome. This is why the Tor Browser is also based on Firefox. If you don't want to use the Tor network, but still want your privacy to be protected, setting this up involves some fairly complex Firefox configuration work. Alternatively, you can let the LibreWolf [1] web browser, a modified Firefox, do the work for you. It does away with gimmicks in the default settings and has been thoroughly hardened by its developers.

LibreWolf is available for various Linux distributions, but also for macOS, OpenBSD, and other operating systems. On Linux, various packages are required for the install depending on the distribution. You also can use an AppImage or Flatpak package. In addition, you will find hints on the project page for all of the installation options [2]. If you install from the repositories and use the Flatpak, you will find a launcher in your desktop menu when you are done.

Getting Started

At first startup, you will not notice much of a difference from the original Firefox. The interface design does not show any serious differences at first glance. Of course, the preinstalled uBlock Origin extension, which filters unwanted ads out of websites, located in the top right corner of the program window next to the address bar, might catch your the eye.

In addition, the default search engine is DuckDuckGo instead of Google, which the original Firefox uses. DuckDuckGo is one of those search engines that values its users' privacy and blocks trackers. LibreWolf lacks the Pocket web application, operated by Mozilla Corporation, which lets you save web pages and articles on remote servers.

If you need to adjust LibreWolf's locale, click on the hamburger menu to the right of the address bar and select Settings from the drop-down menu that opens. A configuration dialog opens that differs significantly from its Firefox counterpart. Click on General in the sidebar on the left and then scroll down the page on the right to the Language option. US English is the default language here.

If you are not happy with that, you can click on the Set Alternatives button to open a small dialog with the available languages. Click Select a language to add, choose, say, Spanish as the language from the drop-down menu that appears, and then click Add to the right. This puts the Spanish localization at the top of the selection dialog, and LibreWolf will use it as the default language for menus and notifications in the future. A final mouse click on OK closes the overlapping window.

Protective Measures

The Settings dialogs available under General vary only slightly compared with Firefox (Figure 1). However, LibreWolf does not let you customize the appearance of web pages in this dialog, some of which modify their color schemes to display content. The browser makes this restriction due to the default security options, where the ResistFingerprinting module is enabled. ResistFingerprinting keeps users from being tracked based on specific web browser settings.

Figure 1: LibreWolf dialogs will be familiar to Firefox users, with a few variations.

Under Startup, LibreWolf only shows an Internet search on the startup screen. Shortcuts and activities, as well as notices from Mozilla (which Firefox enables by default), are left out here. If required, further options can also be restricted: You can prevent sponsored links being displayed on the LibreWolf startup page – this is common practice in Firefox. In addition, pages saved to Pocket do not show up on the startup page, because the developers have completely removed Pocket from LibreWolf. In the Search dialog, all commercial offerings have been removed from the search engine selection, including the Microsoft and Google search engines.

The LibreWolf programmers have made even more significant adjustments in the Privacy & Security category. The Enhanced Activity Protection group does not have three options like Mozilla Firefox does; instead there is only the strict protection variant. Firefox only offers standard protection in this group by default. Activity tracking protection in LibreWolf also extends to social network scripts and various typical tracking methods on websites, such as canvas fingerprinting.

The options for managing cookies and website data are also stricter in LibreWolf than in the original: This data is automatically deleted when the browser is closed, and there is no disk cache in which the browser could cache sensitive data. LibreWolf does not save access credentials and passwords for individual websites or form data by default, and therefore does not automatically fill in the corresponding fields on web pages. However, these options can be enabled by checking the box, just like in Firefox. LibreWolf also deletes the history of websites visited during a session by default when the browser is closed. This means that the history from previous sessions cannot be retrieved when the browser is opened again.

Special Options

The Synchronization category, where Firefox offers data synchronization between multiple endpoints, does not exist in LibreWolf. Instead, the Firefox fork integrates a separate LibreWolf section into the configuration dialog, where you can make numerous security-specific adjustments (Figure 2).

Figure 2: LibreWolf comes with its own configuration dialog where many security-related options can be customized.

Localization is still lacking here: The browser currently only lists the options in this category in English. However, you can understand them even with a limited knowledge of English. To the right of each option, there is a link in the form of a question mark in a circle. Clicking on a the question mark link for an option opens a small explanation below the option and often also shows you optional settings. The parameters can be activated or deactivated by checking or unchecking the boxes to the left of each option.

For savvy browser users, there are two interesting options at the end of the settings list. Clicking All advanced settings opens the manual configuration console, which you can otherwise only access by typing about:config in the browser's address bar. Clicking Open user profile directory opens the file manager with the user profile directory. The root directory with all files and subdirectories appears. Experienced users can use these files to repair damaged profiles.

You can access the profile manager, like in Firefox, by typing about:profiles in the browser's address bar. The profile manager that opens gives you an easy option for creating, deleting, and modifying user profiles.