|Layout Engine||Gecko, Quantum|
Firefox is a web browser developed by the Mozilla Corporation, a subsidiary of the Mozilla Foundation. It is highly customizable by means of add-ons (extensions, plugins, themes), although less-so since Firefox 57.0 (Firefox Quantum) which deprecated legacy extensions in favor of more restrictive WebExtensions. Firefox is also known for it's adherence to Web standards.
For any overview of the various branches and forks of Firefox see Web browsers#Mozilla Firefox.
Privacy & Security Extensions
- Decentraleyes is a local CDN emulator. It is designed to counter tracking via CDN requests by intercepting those requests and serving the same resources from a local cache. This additionally results in faster page load times and reduced bandwidth use.
- LocalCDN is a fork of Decentraleyes that supports more CDNs.
- HTTPS Everywhere encrypts your communications with many major websites according to pre-defined rulesets. It has more personalized support for particular websites than Smart HTTPS. However, if a site does support HTTPS but is not in the ruleset, then HTTPS Everywhere will not redirect you.
Smart HTTPS (repo)
- Smart HTTPS functions differently than HTTPS-Everywhere. It does not use a ruleset and instead tries to bridge a secure connection for every connection. If a secure connection cannot be established it will fallback to HTTP.
- HTTPZ is similar to Smart HTTPS, but offers protection against SSL-stripping.
- Cookie AutoDelete will delete unused cookies upon closing a tab. Supports container tabs (see below).
Multi Account Containers (repo)
- Multi Account Containers is an Mozilla-developed extension that uses part of the security model of Firefox OS to create sandboxed tabs and manage them. May be incompatible with certain extensions.
NoScript Security Suite (repo)
- uMatrix is a powerful matrix-based in-browser firewall that goes well with uBlock Origin. By default it blocks all third party domains, which prevents some websites and especially those serving external resources, from properly functioning - or even loading at all. Broken websites must be unbroken manually by tinkering with the matrix, each change often revealing more cells which themselves must be allowed through the firewall. Barring any major website re-designs, this process is only needed once per domain. But if you're just not in the mood to play Minesweeper, there is what is basically a "rage quit" button to temporarily turn off the firewall at the cost of privacy and security. This feature does not however unblock hosts in uMatrix's pre-defined blocklists.
Privacy Redirect (repo)
- Privacy Redirect does the exact same thing as Invidition.
Track Me Not (repo)
- Track Me Not performs random search queries in the background to obfuscate your real ones. Pairs well with Adnauseum.
- Snowflake turns your browser into a proxy for Tor users living in censored countries.
The following extensions use a deprecated format in modern versions of Firefox. Some forks of Firefox such as Waterfox maintain support.
Classic Theme Restorer (repo)
- Classic Theme Restorer restores the classic Firefox UI.
- VimFx seamlessly adds Vim-like shortcuts and modes without changing Firefox's appearance or behavior. Because VimFx is an XUL extension it is more capable than similar extensions such as Vimium-FF.
- LegacyFox is a shim that patches newer Firefox versions to run this extension in particular. When using this patch, certain extensions may fail to install. If this happens launch Firefox without the
config.jsfile located in
/usr/lib/firefoxdirectory. Add it back after installing the problematic extensions.
- VimFx has an API that can be used to write custom shortcuts in CoffeeScript.
User Script Managers
Userscripts are client-side extensions for websites. User-scripts can alter web pages cosmetically, e.g. wide-github (similar to userstyles/userContent.css). They can also add additional feature, e.g. 4chan-x. You can find userscripts on Userscripts.org (mirror) and Greasey Fork
- Greasemonkey manages userscripts.
- Violentmonkey is more active and more optimized than Greasemonkey.
- Redirector automatically redirects to user-defined urls on a per-hyperlink basis.
Buster: Captcha Solver for Humans (repo)
- Buster tries to solve Captchas on your behalf.
- Gesturefy lets you control the browse with mouse motions.
- Web Archives simplifies finding archived versions of web pages.
- Plasma Integration integrates Firefox with the KDE Plasma desktop environment and KDE Connect. Requires the
plasma-browser-integrationpackage available from your distribution.
- Alternatively there is firefox-kde-opensuse which is supposed to provide better KDE integration beyond what extensions are capable of.
Main article: MetaMask
- MetaMask integrates Ethereum into Firefox.
- PeerTubeify redirects Youtube links to PeerTube instances when available.
Firefox can be modified by CSS rules (called styles) defined in user preference files located under the
For some people it is easier to use a user style manager such as restyle or Stylus to write and maintain styles. However, in Firefox Quantum and newer these extensions are restricted from styling the Firefox browser interface.
The Stylus button that appears after you install it is useful. For instance, to write a userstyle for Firefox, navigate to
chrome://browser/content/browser.xul and select "Write new style -> For this URL", and a template will be made available.
A useful tool for styling is the Inspector. It can be opened by pressing
Ctrl+Shift+C and it'll let you see what elements you can style on the page. To style the browser itself you will need to enable the browser toolbox. The shortcut for opening the toolbox is
Tips 'N Tricks
- Bookmarks Library
- Bookmarks Sidebar
The Firefox URLBar/Awesomebar can be filtered for different types of results.
- typing * searches bookmarks
- typing ^ searches history
- typing % searches open tabs
Firefox can be configured through the
about:config interface. Alternatively, rather than adjust settings manually, you could install a pre-configured
Mozilla bundles a proprietary extension called Pocket in to Firefox. It can and should be disabled by setting
pocket.enabled to false.
DNS over HTTPS and Encrypted SNI
Newer Firefox versions support DNS over HTTPS and Encrypted SNI. For an introduction to ESNI read this article.
Upsides of DoH: Your ISP knows less about you.
Downsides of DoH: Your DNS resolver knows a lot more about you including your browser and operating system, and can set cookies. (Bet you didn't know).
To enable DoH:
network.trr.urito a DoH compliant server such as
DNS over HTTPS is an ESNI prerequisite.
For ESNI set
Better fullscreen for tiling window managers
Turn off annoying fullscreen indicator