Mozilla Firefox is a web browser for Windows, macOS and Linux. It opens websites and web applications in tabs, with bookmarks for returning to saved addresses and controls for deciding which tracking content may load. Its desktop interface also includes tools for examining how a page is presented to visitors and assistive technology.
Tabs, address bar and session restore
Firefox lets you keep several pages open across tabs and browser windows. The address bar can complete bookmarked URLs as you type, so a saved page can be reached without opening the bookmarks Library and finding its entry manually.
The Ctrl+Tab switcher displays thumbnail previews and can cycle through tabs in the order they were most recently used. Recently used ordering is the default for new profiles; the preference can be changed.
Open pages can also carry over between browsing sessions. Mozilla Firefox provides a startup preference to restore the previous session automatically, plus a Restore Previous Session command in the main menu. When quitting through that menu with multiple tabs or windows open, it warns before closing them.
Content Blocking
Firefox separates loading a website from accepting every tracking component associated with it. Content Blocking includes an option to block third-party tracking cookies and another to block all trackers.
Some websites depend on components affected by blocking. Firefox allows exceptions for trusted sites that fail to work correctly with it enabled, so an individual site can be allowed without abandoning the selected blocking settings everywhere else.
Inspecting fonts, accessibility and tracking requests
Mozilla Firefox includes a Page Inspector for examining a loaded page. Its Fonts tab lets a developer view and edit font settings, with controls for both ordinary and variable fonts.
The Accessibility Inspector exposes the page information supplied to assistive technologies. Hovering over an object highlights its corresponding item on the page and displays its role and name. A developer can connect the visible element with its accessibility representation and identify missing information that needs attention.
Firefox also marks requests to known tracking URLs with an icon in the Network Monitor.
