Tracking protection is built in
Enhanced Tracking Protection blocks known trackers automatically, while Total Cookie Protection keeps cookies separated by site to reduce cross-site tracking.
Firefox Browser
Firefox is Mozilla’s free, open-source web browser. It uses the Gecko browser engine and includes Enhanced Tracking Protection, Total Cookie Protection, tab groups, vertical tabs, extensions, customization, Firefox Sync and optional AI controls.
Site privacy policy
Organize busy browsing sessions
Use tab groups, vertical tabs, pinned tabs, Reader View and Picture-in-Picture to keep research, work and everyday browsing easier to manage.
Customize Firefox with add-ons and themes
Install Firefox extensions for privacy, productivity, development and content tools, then adjust themes, toolbars, tabs and the sidebar to match how you browse.
Firefox does not use Chromium
Firefox uses Mozilla’s Gecko browser engine rather than Chromium/Blink, maintaining a separate browser engine for rendering and web platform support.
Move your bookmarks, passwords and history to Firefox
Firefox can import bookmarks, saved passwords, browsing history and selected preferences from supported browsers. After the import, you can choose your privacy settings, extensions, tab layout and other browser preferences.
Enhanced Tracking Protection and Total Cookie Protection
Enhanced Tracking Protection blocks known trackers while you browse. Total Cookie Protection isolates cookies by site, making it harder for third parties to reuse the same cookie to follow activity across different websites.
Use Firefox Sync across your devices
Sync bookmarks, passwords, history and open tabs
Sign in with a Mozilla account to use Firefox Sync across your Firefox installations. You can choose whether to sync bookmarks, passwords, open tabs, browsing history, payment methods, add-ons and browser settings.
Tabs, sidebar tools, extensions and optional AI
Keep tabs and content easier to manage
Reader View reduces visual clutter in articles, tab groups keep related pages together, pinned tabs keep important sites close, and Picture-in-Picture keeps video visible while you use other tabs.
Choose how Firefox looks and works
- Use tab groups, Firefox View and vertical tabs to organize larger browsing sessions
- Open bookmarks, history, synced tabs and other tools from the sidebar
- Add extensions, themes and toolbar changes to customize Firefox
Use AI features only if you want them
Firefox provides controls for supported AI features. You can manage individual AI tools or block generative AI features from appearing in the browser.
Compare Firefox with other browsers and services
The comparisons below focus on browser engines, privacy defaults, extensions, account features and built-in tools so you can see where Firefox differs.
Firefox vs Chrome
Compare Gecko with Chromium/Blink, tracking protection, extensions, tab tools, Sync and account integration.
Compare Firefox and ChromeFirefox vs Brave
Compare Firefox tracking protection and cookie isolation with Brave Shields, along with engines, extensions, Sync and built-in services.
Compare Firefox and BraveFirefox and Google
See how Firefox works with Google Search, Gmail, YouTube and other Google services, and how a Mozilla account differs from a Google account.
Explore Firefox and GoogleFirefox vs DuckDuckGo
Compare Firefox browser features with DuckDuckGo’s browser and privacy services, including tracking protection, extensions, Sync and search.
Compare Firefox and DuckDuckGoFirefox browser features
Built-in PDF editor
Fill forms, add text, annotate PDFs, add images and save changes directly in Firefox.
Protections Dashboard
Review which trackers Firefox has blocked and see information about the privacy protections currently active.
Browser sidebar
Open bookmarks, history, synced tabs, vertical tabs and supported tools beside the page you are viewing.
Optional AI controls
Manage supported AI features individually or block generative AI features from appearing in Firefox.
Vertical tabs
Move open tabs to the side of the browser so longer titles and large tab collections are easier to scan.
Total Cookie Protection
Keep cookies separated by site to reduce the ability of third parties to follow activity across different websites.
Tab groups
Group related pages by project, task or topic, then collapse groups when you do not need them.
Firefox extensions
Add privacy, productivity, development and content tools through the Firefox Add-ons system.
Customize Firefox
Change themes, toolbar controls, tab layouts and sidebar settings to fit the way you browse.
Private Browsing
Close a private window to clear that session’s browsing and search history along with its cookies.
Bookmark manager
Organize saved pages with folders and tags, then keep selected data available through Firefox Sync.
Password manager
Save and autofill logins in Firefox and, if you choose, sync saved passwords through your Mozilla account.
Why people choose Firefox
Firefox combines a non-Chromium browser engine with built-in privacy protection, extension support, tab management, cross-device Sync and extensive customization.
Gecko browser engineFirefox feature
Firefox uses Mozilla’s Gecko engine instead of Chromium/Blink, giving users a major browser option built on a separate engine implementation.
Firefox browser
Enhanced Tracking ProtectionFirefox feature
Known trackers are blocked automatically, and users can review or adjust tracking protection settings for individual sites when needed.
Firefox privacy features
Firefox Add-onsFirefox feature
Firefox supports extensions for privacy, productivity, development, tab management and other browser tasks through its add-ons system.
Firefox extensions
Tab groups and vertical tabsFirefox feature
Built-in tab groups, pinned tabs, vertical tabs and Firefox View provide multiple ways to manage larger browsing sessions.
Firefox tab tools
Mozilla account and Firefox SyncFirefox feature
A Mozilla account can be used with Firefox Sync to keep selected bookmarks, passwords, history, open tabs, add-ons and settings available across devices.
Firefox Sync
Optional AI controlsFirefox feature
Firefox lets users manage supported AI features individually or block generative AI features from appearing in the browser.
Firefox AI controls
Firefox Browser FAQ
Answers about Firefox privacy protection, Gecko, browser migration, Firefox Sync, extensions and Mozilla accounts.
What is Firefox?+
Firefox is a free, open-source web browser developed by Mozilla. It uses the Gecko browser engine and includes privacy protections, tab tools, extensions, customization and Firefox Sync.
Does Firefox block trackers by default?+
Yes. Enhanced Tracking Protection blocks known trackers automatically. Total Cookie Protection is also enabled by default and separates cookies by site to reduce cross-site tracking.
Can I move bookmarks and passwords from another browser?+
Yes. Firefox can import bookmarks, saved passwords, browsing history and selected preferences from supported browsers, so you do not have to rebuild your browser setup from scratch.
What can Firefox Sync synchronize?+
With a Mozilla account, Firefox Sync can synchronize selected bookmarks, passwords, open tabs, browsing history, payment methods, add-ons and browser settings across Firefox installations.
Does Firefox support extensions?+
Yes. Firefox supports extensions and themes through Firefox Add-ons. Extensions can add privacy, productivity, development, tab-management and content tools.
Is Firefox based on Chromium?+
No. Firefox uses Mozilla’s Gecko browser engine rather than Chromium/Blink.
Download Firefox
Get Firefox with built-in tracking protection, flexible tab tools, extensions, customization and Firefox Sync. AI features remain optional and can be managed from browser settings.