Firefox is the window to the world for a lot of Linux users using Fedora, Ubuntu, or Mint. The “out-of-the-box” setup still leaves several doors open, despite the fact that it is likely the most private mainstream browser available. By default, it employs data-hungry search engines, gathers telemetry, and is vulnerable to “fingerprinting”—a method that tracks you even in the absence of cookies.
You don’t have to use a customised fork like LibreWolf in order to harden your browser. You can get the best of both worlds by modifying the official version: full control over your privacy and top-notch security upgrades.
Why Use a “Privacy Browser” Rather Than Manually Harden?
Although specialised projects like LibreWolf and Arkenfox are great, they frequently make judgments on your behalf. It can be challenging to determine which setting caused a website to malfunction. You can learn how to strike a balance between security and usability by hardening Firefox yourself. Additionally, you remain on the official update schedule, guaranteeing that you receive important security fixes as soon as they are released.
Step 1: Turn Off Telemetry
Mozilla gathers “technical and interaction data” in order to make the browser better. This should be turned off if you want the most privacy possible.
Go to Settings > Security & Privacy.
Navigate to Firefox Data Collection and Utilisation.
In this section, uncheck each box.
Pro Tip: Make sure you have a toolkit. telemetry.enabled is set to false by typing about:config in your address bar.
Step 2: Turn Off AI “Enhancements”
AI integrations are being tested in current Firefox versions. If you would rather have a local, lean experience without sending your data to AI servers:
Locate AI Controls under Settings.
Turn the switch to Block AI improvements.
Step 3: Give Up Search Engines That Are Data-Hungry
Although it’s based on tracking, Google is the default.
Navigate to Settings > Search.
Change your default search engine to Startpage or DuckDuckGo. These engines do not use your search history to create a profile.
Step 4: Increase Tracking Security
Firefox’s “Custom” mode is superior to its “Standard” mode.
Select Custom for Enhanced Tracking Protection under Privacy & Security.
All cross-site cookies should be set.
Note: If a website appears “broken,” you can disable this for that particular website by clicking the shield icon in the address bar.
Step 5: Prevent browser fingerprinting
Fingerprinting creates a unique ID for you based on your hardware, typefaces, and screen resolution.
In the URL bar, type about:config.
Look for seclusion. Set resist-fingerprinting to true.
This setting makes it almost impossible to “spot” you in a crowd because your browser appears to be among thousands of others.
Step 6: Use DNS over HTTPS to encrypt your DNS
Typically, every domain you visit is visible to your ISP. DNS over HTTPS (DoH) conceals these requests in an encrypted tunnel.
Navigate to DNS over HTTPS under Settings > Privacy & Security.
Choose Max Protection.
Select a provider such as NextDNS or Cloudflare. Max Protection makes sure that the browser won’t “leak” your request to your ISP in the event that the encrypted tunnel breaks.
Step 7: Enforce HTTPS-Only Secure Connections
Your browser should never allow unencrypted connections.
Navigate to HTTPS-Only Mode under Privacy & Security.
In every window, choose Enable HTTPS-Only Mode.
Firefox will alert you before allowing you to access an outdated website that does not support security.
Step 8: NoScript’s “Nuclear Option”
Malicious JavaScript is used in the majority of web attacks. The NoScript extension blocks all scripts by default.
Install the NoScript Security Suite from the Mozilla Add-ons store.
At first, it will break many websites. All you have to do is click the icon and “Trust” the domains (like your bank or email) that you know are secure. It is the best defence against “zero-day” web exploits.
As a result, you now have a “Hardened” Firefox that protects you from harmful malware, resists sophisticated tracking, and transmits less data to the cloud. You are now the administrator of your privacy, not just a user.