This article overviews how to configure Firefox to enhance security and privacy.
- 1 Configuration tweaks
- 1.1 Enable Anti-Fingerprinting
- 1.2 Enable tracking protection
- 1.3 Change browser time zone
- 1.4 Change user agent and platform
- 1.5 WebRTC exposes LAN IP address
- 1.6 Disable 1024-bit Diffie-Hellman primes
- 1.7 Disable telemetry
- 1.8 Enable Do Not Track Header (DNT)
- 1.9 Disable geolocation
- 1.10 Disable Safe Browsing service
- 1.11 Disable WebGL
- 2 Extensions
- 2.1 HTTPS Everywhere
- 2.2 uBlock Origin
- 2.3 AdNauseam
- 2.4 Adblock Plus
- 2.5 Privacy Badger
- 2.6 Disconnect
- 2.7 NoScript
- 2.8 uMatrix
- 2.9 Cookie AutoDelete
- 2.10 RefControl
- 2.11 RequestPolicy Continued
- 2.12 Decentraleyes
- 2.13 CanvasBlocker
- 2.14 Random User Agent
- 2.15 Privacy Settings
- 2.16 Stop Fingerprinting
- 3 Remove system-wide hidden extensions
- 4 See also
The following are privacy-focused configuration tweaks to prevent browser fingerprinting and tracking.
In addition, see the following links:
- MozillaWiki:Privacy/Privacy Task Force/firefox about config privacy tweeks - a wiki page maintained by Mozilla with descriptions of privacy specific settings.
- How to stop Firefox from making automatic connections - Is an annotated list of corresponding Firefox functionality and settings to disable it case-by-case.
- ffprofile.com - You select which features you want to enable and disable and in the end you get a download link for a zip-file with your profile template. You can for example disable some functions, which send data to Mozilla and Google, or disable several annoying Firefox functions like Mozilla Hello or the Pocket integration.
- pyllyukko/user.js - Firefox configuration hardening and documentation
Mozilla has started an anti-fingerprinting project in Firefox, as part of a project to upstream features from Tor Browser. Many of these anti-fingerprinting features are enabled by setting
There is no user-facing documentation about this flag, and Mozilla does not recommend users enable it, since it will break a few websites (it exists mostly to make life easier for the Tor Browser developers). But it does automatically enable many of the features listed below (such as changing your reported timezone and user agent), as well as protection against other, lesser-known fingerprinting techniques. See the tracking bug that lists many of these features.
Enable tracking protection
Firefox gained an option for tracking protection. It can be enabled by setting
Apart from privacy benefits, enabling tracking protection may also reduce load time by 44%.
Note that this is not a replacement for ad blocking extensions such as #uBlock Origin and it may or may not work with Firefox forks. If you are already running such an ad blocker with the correct lists, tracking protection might be redundant.
Change browser time zone
The time zone of your system can be used in browser fingerprinting. To set Firefox's time zone to UTC launch it as:
$ TZ=UTC firefox
Or, set a script to launch the above (for example, at
Change user agent and platform
You can override Firefox's user agent with the
general.useragent.override preference in
The value for the key is your browser's user agent. Select a known common one.
- The value
Mozilla/5.0 (Windows NT 6.1; rv:52.0) Gecko/20100101 Firefox/52.0is used as the user agent for the Tor browser, thus being very common.
- The #Enable Anti-Fingerprinting option also enables the Tor browser user agent and changes your browser platform automatically.
To change the platform for firefox, add the following
string key in
Select a known common platform that corresponds with your user agent.
Win32is used as the platform for the Tor browser, corresponding with the user agent provided above.
WebRTC exposes LAN IP address
about:config and set:
false. (only if you want to completely disable WebRTC)
Disable 1024-bit Diffie-Hellman primes
Then consider checking your SSL configuration at https://www.howsmyssl.com/.
false and/or disable it under Preferences, Advanced, Data Choices.
Enable Do Not Track Header (DNT)
true or toggle it in Preferences > Privacy > Manage your Do Not Track settings.
Disable Safe Browsing service
Safe Browsing offers phishing protection and malware checks, however it may send user information (e.g. URL, file hashes, etc.) to third parties like Google.
To disable the Safe Browsing service, in
In addition disable download checking, by setting
WebGL is a potential security risk. Set
about:config if you want to disable it.
HTTPS Everywhere is an extension which encrypts your communication with a website. It forces a connection over HTTPS instead of HTTP wherever possible.
HTTPS Everywhere will be automatically configured and enabled upon restarting Firefox. For information on how to set up your own rules for different websites please visit the official website.
uBlock Origin is a lightweight, efficient blocker which is easy on memory and CPU. It comes with several filter lists ready to use out-of-the-box (including EasyList, Peter Lowe's, several malware filter lists).
The lead developer of uBlock forked the project and created uBlock Origin. As of July 2015, most of the development is being done on uBlock Origin and the codebases are deviating substantially.
AdNauseam is a lightweight browser extension that blends software tool and artware intervention to fight back against tracking by advertising networks. AdNauseam works like an ad-blocker (it is built atop uBlock-Origin) to silently simulate clicks on each blocked ad, confusing trackers as to one's real interests .
Privacy Badger is an extension by the EFF that monitors third-party trackers loaded with web content. It blocks trackers once they appear on different sites. It does not block advertisements in the first place, but since a lot of ads are served based on tracking information these are blocked as well. For more information on the mechanism, see its FAQ.
Disconnect is a open source project aimed at stopping 2,000 third-party sites from tracking a user. It encrypts data sent to popular sites and claims to loads web pages 27 percent faster. Disconnect shows its users, in real time, how many tracking attempts from Google, Twitter, Facebook, and more are stopped. It categorizes tracking attempts into advertising, analytical, social, and content, which makes it easy to monitor how one is being tracked.
Disconnect can also stop side-jacking, which utilizes stolen cookies to steal personal data. It is easy to use and well supported. It can be added to Firefox at the official website.
Once installed you can configure settings for NoScript by either clicking its icon on the toolbar or right clicking a page and navigating to NoScript. You will then have the option to enable/disable scripts for the current page, as well as any third party scripts that the page is linking to. Alternatively you can choose to enable scripts temporarily for that session only.
Be aware a lot of modern websites use scripts for layout purposes, hence content may look different. For example, failed rendering due to missing fonts might occur on websites that load fonts at runtime via scripts, which were blocked by NoScript.
For more detailed configuration see the NoScript FAQ.
For more Information visit the project site.
Cookie AutoDelete is an extension that deletes cookies as soon as the tab closes. Supports automatic and manual cookie cleaning modes. (Support for clearing LocalStorage was added in version 2.1, but only for Firefox versions 58+. The same release added support for first party isolation, but only for Firefox versions 59+).
RefControl is an extension to control what gets sent as the HTTP Referer. Once installed RefControl can be configured so that no referer gets sent when navigating to a new webpage. This prevents the server from knowing which website you originated from.
To do this open RefControl's preferences and change the setting for "Default for sites not listed:" to <Block>.
RequestPolicy Continued (a successor to the original RequestPolicy) is an extension for Mozilla browsers which lets you have control over cross-site requests. It also lets you blacklist or whitelist requests by default. Disabling unnecessary cross-site requests leads to better privacy, safety and faster browsing.
Decentraleyes protects you against tracking through "free", centralized, content delivery. It prevents a lot of requests from reaching networks like Google Hosted Libraries, and serves local files to keep sites from breaking. Complements regular content blockers.
CanvasBlocker Blocks or fakes the JS-API for modifying <canvas> to prevent Canvas-Fingerprinting.</canvas>
Random User Agent
Random User Agent rotates complete browser profiles (from real browsers/devices) at a user defined time interval. It includes many extra privacy enhancing options.
Privacy Settings provides a toolbar panel for easily altering Firefox's built-in privacy settings.
Stop Fingerprinting disables / modifies some browser APIs that would otherwise allow browser fingerprinting. However, this addon is not compatible with newer versions of Firefox (57+).
Several extensions, hidden to the user, are installed by default in
/usr/lib/firefox/browser/features. Many can be safely removed via
rm extension-name.xpi in order to completely remove unwanted features. Many of these extensions are not enabled by default and have a menu option for enabling or disabling. Note that any files removed will return upon update of the package. Below are a few examples of these extensions and their features.
email@example.com- "Activity Stream" which replaces the new tab page. See 
firstname.lastname@example.org- Search telemetry. See also #Disable telemetry.
See also  for a full list of system extensions including README files describing their functions.