In Firefox in Windows operating system, when pressing the backspace key, the web page active in the window or tab will be going back one page, an action that similar to both Firefox and IE browser’s “Back” button, while Shift+Backspace will go forward. The backspace key is mapped to “Back” function in Firefox for Windows is for consistency with Internet Explorer.
On the other hand, Firefox in Linux by default does not map the backspace key to “Go Back” function to improve consistency with other applications running on Linux. Instead, the page will scroll up or down (when pressing Shift+Backspace key together).
The backspace as Back button feature can be easily turned on or off depending on user preference. Thus, Firefox for Windows users can disable the back function mapping to backspace key, and Firefox for Linux can enable the backspace to map to Back function easily, by using the following Firefox pref.
Type about:config in Firefox Location Box, and then confirm the warning message. Then locate the following preference name:
Change the “browser.backspace_action” to one of the following values to reflect your intention on how the Backspace key should behaves:
0: Pressing [Backspace] will go back a page in the session history and [Shift]+[Backspace] will go forward. (Default in Windows)
1: Pressing [Backspace] will scroll up a page in the current document and [Shift]+[Backspace] will scroll down. Except Camino that does not implement any behavior for the value 1, which is unmapped. (Default in Linux builds before 2006-12-07)
Any other integer number: Any other integer value will simply unmap the backspace key. In Linux builds after 2006-12-07, the default is 2.