JavaScript is a standard programming language that can be included in web pages to provide functionality such as menus, sounds, and other interactive features. By default, Firefox enables the use of JavaScript and requires no additional installation.

However, JavaScript can also be used to do things that some users find undesirable. While the JavaScript settings in Firefox are configured to provide a safe experience on the web, you can review the settings to ensure that they meet your needs.

Table Of Contents

• Enabling and disabling JavaScript
• Advanced JavaScript settings
• Add-ons

Enabling and disabling JavaScript

In Firefox, you can configure whether JavaScript in web pages is permitted to execute or not. To allow JavaScript in Firefox:

1. At the top of the Firefox windowOn the menu bar, click on the ToolsFirefoxEdit menu, and select Options...Preferences....
2. In the OptionsPreferences window, select the Content panel.
   1. Enable JavaScript: Select this option to permit JavaScripts to execute on your computer.
   2. To change advanced settings, click Advanced....
      
      
      
      
3. Click OKClose the preferences window.

Advanced JavaScript settings

Through the Advanced JavaScript Settings window, you can configure the permissions for JavaScripts.

• Move or resize existing windows: To prevent JavaScripts from changing the position or size of existing windows, deselect this option.
• Raise or lower windows: This option allows sites to place windows below or above existing windows.
• Disable or replace context menus: When you right-click an item, a sub-menu may appear. This menu, called a "context menu," can be disabled through JavaScripts. To prevent them from disabling context menus, deselect this option.
• Hide the status bar: The status bar is the area at the bottom of each window that indicates your current location and the destination locations of hyperlinks. Through JavaScripts, the status bar can be hidden from display, which prevents you from identifying locations of pop-up windows. To prevent hiding the status bar, deselect this option.
• Change status bar text: Through JavaScript, web sites can add their own text to the status bar, which prevents you from identifying locations. To disable overwriting the status bar, deselect this option.

Add-ons

• NoScript: Allows you to permit JavaScript, only from web sites you trust.

Based on information from JavaScript (mozillaZine KB)