How to Open Firefox’s Private Browsing Mode with a Keyboard Shortcut Jan 11, 2021, 9:00 am EDT | 1 min read If you’re browsing the web with Mozilla Firefox and you’d like to quickly open a Private window, there’s no need to reach for a menu. Here’s how to start private browsing in Firefox with just a keyboard shortcut on Windows, Linux, and Mac. First, open “Firefox.” With any Firefox window active, press one of the following shortcuts depending on your computer platform. Windows or Linux: Press Ctrl+Shift+P Mac: Press Command+Shift+P After that, a new Private window will open.