Enable JavaScript in Firefox

Updated at: Mar 22, 2022

This guide will step you through the process of enabling JavaScript in Firefox.

1. Click into the Address Bar

   The more advanced settings for Firefox are only available by visiting a special url.

   Start by clicking into the Address Bar at the top of your Firefox window.

   

2. Visit the Advanced Configuration url

   In the address bar, type in about:config and press enter. You do not need to put in http:// or www or anything like that; simply put about:config and press the Enter key on your keyboard.

   

3. Accept the warning about changing advanced settings

   Because about:config will give you lots of advanced options which can potentially mess up Firefox, you will be warned about not changing anything you're not sure about. Click the "Accept the Risk and Continue" button.

   

   This warning will appear each time you visit about:config unless you untick the "Warn me when I attempt to access these preferences" checkbox. I recommend keeping this box ticked to remind you each time!

4. Type "javascript" into the search field

   Because there are so many settings, the easiest way to find the JavaScript setting is to start to type "javascript" into the search box. As you type this, Firefox will reduce the number of settings shown until just the JavaScript based settings appear.

   

5. Find the "javascript.enabled" preference

   One of the settings which you can see should be called "javascript.enabled" in the "Preference Name" column. If you have JavaScript disabled, you should notice that it will be shown in bold text.

   

   This is because it is not the default setting: the default setting is for "javascript.enabled" to be "true". So that is the setting you need to change.

6. Reset the JavaScript preference

   Because you don't currently have JavaScript enabled, you'll have the ability to "Reset" that preference to the default - which is "enabled". On the right-hand side of the advanced options window, you will see the "Reset" button for the JavaScript option . It kind of looks like an "undo" icon. Alternatively, you could click the toggle icon for that setting which will toggle the value between true and false

   

   When you click the reset button, it will change the Javascript setting back to "enabled".

   Note: If you don't see the javascript.enabled setting in bold, saying false with the reset button in the right-hand column the you probably haven't actually disabled JavaScript! You might have some kind of browser extension/addon which is blocking JavaScript instead. Try disabling it to cause JavaScript to work again.

7. Javascript is now enabled. Close the settings tab.

   Now that you have clicked the "reset" icon, JavaScript will have been changed back to the default setting which is "enabled". You can simply close the tab with all the Advanced Configuration settings on it and resume browsing the internet.

   

   Click here to confirm that JavaScript is now enabled.

More guides and help for Firefox

Need more help with Firefox? Read our other Firefox guides.