Third-party tracking cookies are now blocked for all users by default. See Content blocking for more information about how Firefox protects you against tracking.

Cross-site tracking cookies are now blocked for all users by default. See Enhanced Tracking Protection for more information about how Firefox protects you against tracking.

Third-party cookies are cookies set by a website other than the one you are currently on. For example, cnn.com might have a Facebook like button on their site. That like button will set a cookie that can be read by Facebook. That would be considered a third-party cookie.

Some advertisers use these types of cookies to track your visits to the various websites on which they advertise. If you are concerned about this, you can disable third-party cookies in Firefox.

Third-party cookie settings are available in the OptionsPreferences page's Privacy & Security panel: Click the menu button Options . Preferences . Select the Privacy & Security panel and go to the Cookies and Site Data section. From the drop-down next to Accept third-party cookies and site data, select Never . Note: After browsing with this setting, you won't be able to properly view some of your favorite websites, so an intermediate solution is to set it to From visited. That will allow third-party cookies coming from previously visited websites. Close the about:preferences page. Any changes you've made will automatically be saved.