Open a blank, private tab: Tap the Firefox Menu button (either below the screen on some devices or at the top-right corner of the browser) , then tap New Private Tab.
Open a link in a private tab: Long-tap on a link to bring up a menu and choose Open link in Private Tab.
View open private tabs
Tap the tab icon at the top of your screen, then tap the mask icon to view the sites you've opened in Private Browsing.
To close a tab, tap the X next to the tab you want to close. You can also close all open tabs by tapping the menu button, then Close Private Tabs.
Warning: Private Browsing doesn't make you anonymous on the Internet. Your Internet service provider, employer (if using your employer's WiFi, for example), or the sites themselves can still track what pages you visit.