How to Disable JavaScript in Firefox

Firefox Start Page

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You occasionally need to disable JavaScript for development or security purposes, or maybe you need to turn off JavaScript for performance reasons or as part of a troubleshooting guide.

Regardless of your reasons, this step-by-step tutorial explains how it's done in Mozilla's Firefox browser. Disabling JavaScript should only take a few minutes, even if you're unfamiliar with how to use Firefox's settings.

You can also turn off JavaScript in Chrome and other browsers.

How to Disable JavaScript in Firefox

  1. Enter about:config into the address bar in Firefox. This is the space where you normally see a website's URL. Make sure to not put any spaces before or after the colon.

    Screenshot of the about:config screen in Firefox
    Jon Fisher
  2. A new page will appear that reads, "This might void your warranty!" Click or tap I accept the risk! to see a huge list of Firefox preferences.

    This button will read I'll be careful, I promise! if you're using an older version of Firefox. It's always recommended to keep your software fully updated.

  3. Enter javascript.enabled into the search box at the top of the page.

  4. Double-click or double-tap this entry so that its "value" changes from true to false.

    Android users should select the entry just once and then use the Toggle button to disable JavaScript.

    Screenshot of the javascript.enabled setting in Firefox
    Jon Fisher 
  5. JavaScript is now disabled in your Firefox browser. To re-enable it at any time, return to Step 4 and repeat that action to reverse the value back to true.