Enable JavaScript in Firefox

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

The screenshots below are taken from Mac OS X, but the process is the same on Windows.

  1. Click into the Address Bar

    The more advanced settings for Firefox aren't accessible from the standard "Settings" controls. You need to go to a special address to be able to change them. To do this; you'll need to type in a special url and then load it.

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

    The Firefox address bar

    The Address Bar is at the top of the Firefox window and usually shows the URL of the website you're looking at.

  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.

    Screenshot showing where to type about:config into

  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 "I'll be careful, I promise" button.

    The warning that Firefox gives you about changing advanced options

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

  4. Can now search for advanced settings to change

    Firefox has hundreds of advanced options which can be changed. To make it easy to find the ones that you are looking for, Firefox will give you a search feature.

    The search interface for the advanced firefox configuration options

    There is a search box at the top of the page which you can use to search. Alternatively, you can click Show All to see a huge listing of all the options.

  5. 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.

    The advanced settings being narrowed down by searching for javascript

  6. 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.

    The JavaScript setting highlighted in the list

    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.

  7. 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

    Screenshot showing the Reset preference button

    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.

  8. 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.

    Now the setting is changed to True

    Click here to confirm that JavaScript is now enabled.

Looking for guides to enable JavaScript in other web browsers?

Here are some guides for other web browsers like Safari or Chrome.

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