Mozilla Firefox is disabling the browser's backspace key to prevent users from accidentally losing data entered into forms.

In 2014, Google removed the ability to return to a previous page using the backspace key, as it could cause data entered into forms on the current page.
“It would be useful to determine how often backspace is used as a shortcut for the “back” action, so we can understand if we need to modify the UX in some way to avoid accidental loss of form data due to mistyping the backspace key,” Google Chrome developers had reported in 2014.
Seven years ago, Mozilla opened a bug post to discuss whether the backspace key should be disabled, but decided not to make any changes.
Over six years later, Mozilla finally decided to implement this change since Firefox and Internet Explorer 11 are the only browsers that support this keyboard shortcut.
“To avoid data loss when filling out forms, the Backspace as a navigation shortcut for “Go Back a Page” is now disabled. To re-enable the Backspace keyboard shortcut, you can change the preference about:config browser.backspace_action to 0. You can also use the recommended shortcut Alt + Left Arrow (Command + Right Arrow on Mac),” Pascal Chevrel added in the Firefox Nightly 86.0a1 release notes.
According to TechDows, which first reported this change, the change is now available in the latest version of Firefox that users are testing.
For those who wish to continue using the backspace key, you can re-enable it in about:config using the following steps:
1. Type about:config in the Firefox address bar.
2. Search for browser.backspace_action and change its value to '0'.
Once the setting is enabled, you can use the backspace key to return to the previous page in Firefox.
Information source: bleepingcomputer.com
