The backspace key in the Mozilla Firefox browser is like this. If you are on a web form and entering text, the backspace key does exactly what you want it to. It moves the cursor to the left one space with each keystroke, deleting the character that was there. But what if the field you were typing in has lost the focus? Then, the backspace key becomes a browser navigation key, and Firefox treats it as if you've hit the Back button on your browser. Typically this means you've lost everything you just typed in, and you get to do it all over again.
This can be the height of frustration, especially if you spent a long time carefully crafting a witty takedown of someone that was wrong on the Internet (a full-time job, I well know).
Fortunately, the Firefox team believes in the concept of providing plenty of rope, and the browser is near infinitely customizable. The behavior of the backspace key is one of those options that can be changed.
The behavior of the backspace key is controlled by the browser.backspace_action configuration setting. All of the valid values for this option can be found in the Mozilla Knowledgebase. If you want to disable this behavior, you should set this option to a value that is not '0' or '1'. Mozilla uses '2' as an easy convention, and actually sets that as the default in the latest Linux builds. Why they don't set that as the default for all versions I don't know, but that's a rant for another day.
If you're already a Firefox configuration pro, then you can skip the rest of this article. If you've never changed Firefox before, here's a simple step-by-step on what to do (all screenshots taken using Firefox 16.0.1):
- Open a new tab and type "about:config" as the URL
- Firefox will present a warning page. Leave the "show this message next time" option checked and click the "I'll be careful, I promise!" button
- In the search bar, type "browser.backspace_action"
- Double-click on the configuration option named "browser.backspace_action" and a dialog box will pop up that lets you change the value
- Set the value to "2" and click OK
- Close the tab that you opened (there is no final save button to click; changes are saved automatically)
- The change takes effect automatically. There is no need to restart your browser.
- The backspace key should no longer act as the "Back" navigation button