Panorama allows you to drag-and-drop open tabs into groups, such as social networks or news sites. When you view a website, you'll only see the other tabs in that group, rather than seeing lots of tiny tabs, or having more tabs than can display on the window.
The Panorama icon in the top right-hand corner of the browser window lets users switch in and out of the mode.
The web browser also includes Firefox Sync that enables users to sync bookmarks, history, passwords, form-fill data and even open-tabs across different computers and mobile devices that use the browser.
Mike Beltzner, director of Firefox, said in a blog the new features "offer more control over your web experience".
"This release lets you own and control your personal web experience by syncing your data across devices, and by helping you organise your tabs in order to juggle and prioritise your busy online life."
The latest beta version of Firefox 4 can be downloaded now from Mozilla's dedicated web page.
See also: Mozilla to silently update Firefox 4