Firefox has been in a weird state for a while now. Chrome and Chromium's dominance is complete, making up 62.85% and 75%, respectively, of the browser market in 2023. Firefox has been in consistent decline, but in recent years, Google has repeatedly attempted to use Chrome's dominance to advance technologies that make it easier to track users online and protect advertising revenue. Most recently, for example, Google has caused controversy with its Manifest V3 changes to the Chrome Extensions API.This push to control underlying web technologies has been concerning, highlighting the importance of browsers and tools not built exclusively on Chromium. Firefox is one of the largest holdouts from Chromium, and Mozilla and the open-source community have quietly been building up a great suite of privacy-focused tools and extensions to help protect your privacy online. All the extensions we'll cover today are also FOSS (Free and Open Source Software).

Managing extensions in Firefox

Firefox makes managing and installing extensions easy, via the dedicated extensions button in the toolbar by default. From this extension dropdown, you can access an extensions' settings, add and remove extensions, or pin extensions to your toolbar. Using the Manage extensions button at the bottom also allows you to view themes and addons installed in Firefox. You can also access this page by typing about:addons in the search menu.

Scrolling down to the bottom of the addons page gives a link to Mozilla's addon store.

1 Multi-Account Containers

Arguably one of the biggest reasons to switch to Firefox

One of the best-inbuilt features of Firefox is the concept of multi-account containers. Containers are designed to enhance your privacy and security by keeping different browser tabs isolated within the same browser window. Each container can be considered its own segregated browser, with no sharing of cookies, local storage, or session data, while still being able to persist sessions. Container tabs are fantastic for privacy, allowing you to limit your exposure entirely to tracking cookies and keep problematic sites entirely separate.This can be used for more than privacy, for example, allowing you to sign in to two different accounts on the same site and keep your browsing sessions distinct. It's great if you've got work and personal accounts with the same services.Different containers are color-coded as tabs within your normal browser window.

You can get started with multi-account containers by installing an extension from the Firefox Add-ons store, and the source is on GitHub.There are also some great social-media-specific container extensions, like Facebook Container. This extension automatically opens all Facebook-owned sites in a new container specifically for Facebook. You can set this up for any site within the base Multi-Container extension, but it takes some more configuration.

2 uBlock Origin

The essential extension for privacy online

uBlock Origin is one of the de-facto leaders in ad or content blocking, and is one of the basic tools you should install to protect your privacy. Most popular web apps, from Google Docs to Outlook, are written with Javascript (or transpiled to it), which runs locally in your browser and is a core reason why the web has moved from static HTML webpages to full progressive web apps. This influence, however, makes Javascript one of the single biggest attack vectors for everything from in-browser cryptominers to injected keyloggers. uBlock Origin maintains a large set of rules and blocks, some of which are enabled by default and some of which are optional.While it's easy to get started with, uBlock Origin is a comprehensive tool with powerful customization. It also allows you to create rule lists and content filters, as well as set up exceptions for trusted sites and content. It also features an advanced mode, which opens up an extensive range of settings. Unless you're an expert, we don't recommend this mode, as it can be easy to misconfigure and end up with either an entirely broken web browsing experience or worse privacy than when you started. But if you're interested in really taking your uBlock Origin setup to the next level, there are some great resources in the uBlockOrigin subreddit.You can install uBlock Origin through the Firefox Add-ons store.

3 HTTPs Everywhere

A no-brainer for improving your security

Ensuring you're using HTTPS at all times is one of the most important ways to protect yourself online. If you're using the internet in public or on Wi-Fi you don't trust, HTTPS is your first (and sometimes only) line of defense against malicious actors collecting or sniffing your traffic. Forcing HTTPS also prevents dangerous man-in-the-middle attacks by forcing certificate security. For example, if a website has been quietly replaced by a malicious page, Firefox will warn you that the certificate is not valid. This is a great tool to prevent information leakage and is essential if you're in a setting where the exposure of your browsing data could be serious.HTTPS, by default, is now supported natively in Firefox. You can enable it by going to Settings > Privacy & Security > HTTPS-Only mode and selecting Enable HTTPS-Only Mode in all windows.

4 Enable DNS Over HTTPS

DNS has been a pain point for years

The relative insecurity of DNS has been identified as a privacy problem for years now, and encrypting DNS traffic is one of the big benefits of using a great VPN. DNS over HTTPS does what it says on the tin and encrypts all DNS requests originating from your browser with the same SSL/TLS encryption used for your normal traffic. Firefox now supports DNS over HTTPS natively, with several tiers of protection you can enable.By default, Firefox uses secure DNS whenever it's available but reverts to your local DNS cache if required. It doesn't enforce DNS-over-HTTPs everywhere. You can tweak this by changing your strictness setting. At its maximum protection setting, Firefox will exclusively use the DNS provider you specify and always use DNS-Over-HTTPs. You'll see a warning if secure DNS isn't available on a site. Enabling DNS over HTTPS shouldn't negatively affect your browsing experience and is a small but significant mitigation to the risk of your traffic being collected or used in an attack.You can find Firefox's DNS Security Settings under Settings > Privacy & Security > Scroll down. There's also a guide to this available on Mozilla's website.

5 Decentraleyes

Localize your CDNs for added performance and privacy

Much of the internet relies on shared content from content delivery networks (CDNs) run by large organizations online. These might be libraries or scripts that are common across websites for tracking, ads, UX/UI, or features such as chat and comment boxes or cookie popups. This content is often identical across multiple websites. Decentraleyes intercepts traffic to these CDNs and replaces them with a locally stored copy, improving performance while removing the ability for these CDNs to track your usage across multiple sites. Decentraleyes requires no setup and mostly runs automatically in the background.There is an added benefit to using local storage for this kind of content: It's much faster. By using a local copy, latency to return these libraries can be significantly reduced, making your overall browsing experience faster.You can install Decentraleyes through the Firefox Add-ons store or check out the source on Gitlab.

Take your privacy into your own hands

Protecting your privacy online can feel daunting, even pointless. But with some relatively small tweaks, you can vastly improve the situation. It's important to be proactive about privacy, and some great tools are being built to help protect it. This only becomes more relevant in the face of an internet increasingly dependent on targeted advertising.