Firefox's protection against fingerprinting
Fingerprinting Protection is an experimental feature that is under heavy development in Firefox.
Compact mode workaround in Firefox
Learn about a workaround to activate compact mode, if you need to. This feature isn't supported and we still recommend using normal mode.
Configuration Editor for Firefox
The Configuration Editor (about:config page) lets you view, change, or reset advanced preference settings in Firefox. Learn more.
Multi-Account Containers
Add Container tabs to Firefox with the Multi-Account Containers add-on, to separate your work and personal browsing.
How to enable Windows SSO login in Firefox
Use Windows single sign-on (SSO) to log in to Microsoft, work, and school accounts with credentials from your Windows 10 or 11 operating system.
Control audio or video playback with your keyboard
This page explains the technical documentation on how to control media in Firefox by using the Media Session API.
About Studies
How to opt out of studies
Canary domain - use-application-dns.net
Network administrators may configure their networks to modify DNS requests for the following special-purpose domain, called a ''canary domain''.
Firefox Nightly Error Collection
Learn about Firefox Nightly's error collection policy.
Sync custom preferences
Firefox Sync allows you to sync your preference settings across all your Firefox Desktop devices. Learn more.
DOM events changes introduced in Firefox 66
Firefox 66 introduced DOM events changes for compatibility with legacy content. Learn more.
Firefox advanced customization and configuration options
Two types of advanced Firefox customization options, about:config and userChrome.css modifications, are not recommended. Learn more.