Firefox: Initial/basic hardening

A collection of advice, tips, and plugins to make Firefox a little more privacy friendly. These steps should be taken before you do anything else with that browser.

(Edition 8)

Out-of-the-box Firefox is just another privacy invading browser. Not the worst there is, but still. You will often meet the statement that it can be made (more) private or that it can be (somewhat) hardened. What this statement really means is that it is certainly not so per default and that you will need to spend lots of time on work to make it less offensive, effectively sabotaging several built-in functions.



This guide has been created because Firefox may sometimes be hard to escape. Eg it is currently the only browser available on a fresh install of some operating systems. Also, some software developers are contractually bound to support only 3-4 "major" browsers, which means that sometimes important software (like, say online banking) just will not work in an alternative browser.

Of course this assumes that browsers like Edge, Chrome, Opera, and Chromium with all its derivatives are not viable alternatives. So, as the lesser evil you may be forced to put up with it in some situations and due to this you should take at least some steps to improve your privacy.

In the general context of "privacy" and even "security", before venturing into browser "hardening" you should consider some related issues like eg. Firewall and/or VPN. Also, you should do a little reading up on how to modify your online behaviour so that you improve your privacy. These issues are not covered here.

Below advice is only the most basic, only related to the browser level, and then just for one particular browser - you should really do additional research yourself.

It will probably be necessary to install an alternative browser to browse for information to assist you while configuring Firefox, hence keeping Firefox off-line. Or, to replace Firefox altogether.

First time browser is online, or first time you are online?

Important: The first time you start up Firefox you should have no connection to the Internet at all. As soon as you start up Firefox with an active (open) internet connection Firefox will use it for communication - before you are even given the option to visit any web site. Meaning that you could be exposed to whatever you fail to disable before that time.

So, complete the primary steps below without having an internet connection open at the same time that you have Firefox open.

After completing the initial setup, on your first time online you should visit no web site at all. The only things you should do are described in the secion on relevant privacy extensions / plugins / add-ons.

Configure Firefox: Privacy and security settings

Linux (Debian) only

Before you start Firefox for the very first time, open up a terminal window and install uBlock Origin from repository:

# sudo apt install webext-ublock-origin-firefox

... then:

I could offer specific recommendations but I won't as it's a large topic, and best practices tend to change a little with each Firefox update. See Further reading below.

You may want to try "Librefox" - a set of hardening configurations for an existing Firefox install:

At this point you should have an alternative browser available for doing research while you do the initial off-line configuration.

Install hardening browser plugins

Do not just take below suggestions at face value. Investigate first. Some may have been OK at the time of writing and since deteriorated, or I may have made an error or a bad judgement in compiling the list (or made some assumptions that do not apply to your specific case)

Some suggested extensions

Please don't just download/install all of these in one go, as some may do (some of) the same tasks that others do. Installing too much stuff will slow down your browser.

Update/notification, December 2021:

The Electronic Frontier Foundation has issued a warning that Alphabet ("Google") will update the software policy for their Chrome browser so that some privacy enhancements / plugins will no longer work as intended. In the same warning it was revealed that Firefox is planning to adopt at least some of the exact same policy, labelled "Manifest version 3".

Search engine alternatives

Next, remember to search for a new web search provider and add at least a few different ones to switch between when searching (and DO remember to switch search engine ever-so-often).

Just delete all the search engines that are installed by default. Those are installed because they paid for it, there is no reason to believe that they will respect your privacy.

Search engine suggestions (alphabetical order)

(not all are privacy-focused, and some may be so more by claim than by action)

You add these by navigating to their web page and when there placing your mouse cursor in the Firefox search input field, clicking the drop-down (downward pointing arrow) inside the field, and selecting the option "add ... to Firefox".

Here are a few starting points regarding search and privacy:
Please use this link only as part of your research, not as all of it

Now you may wish to visit some web sites

First, clear history, preferably all of it, and shutdown/restart Firefox.

To clear history press three keys at the same time: [ctrl] + [shift] + [delete]. Do this regularly when browsing.

Only AFTER performing the above steps should you visit the first web site using Firefox. You may want to first visit the web sites mentioned in Further reading below.

You will want to spend some time on each of the steps above. You may even want to first download an alternative web browser to assist you in making informed decisions.

Using safe mode / private windows / incognito

Just a quick mention... You may want to use "private mode". While this will improve the default privacy level, it should NOT be considered "private browsing" in any sense of the word.

Use alternative browsers, and more than one

This page and the fact that there are several privacy-oriented browser alternatives should give you a hint that the main focus of Firefox is not your privacy, although it is not even among the worst there is. Also, Firefox is not even close to being lightweight.

As a final piece of advice, an easy way to increase your privacy is to switch browser from time to time, and/or to use certain browsers for certain types of tasks while not for others. You may think this is hard to do on older hardware as the amount of available browsers (eg for 32 bit architecture) may appear limited. It is far from impossible though.

Some suggestions for browser alternatives -- even for old hardware -- are found here:

List: Alternative Browsers for Linux (for Lightweight and Privacy)

Further reading


(This page was initially part of The Useful Linux After-Install Todo List. It was extracted in order to make the former list smaller)