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How to Allow or Block JavaScript in Firefox Computer

Learn how to allow or block the JavaScript (JS) execution for all sites on Firefox browser. JS make site interactive, likewise it's also prone to hacking.

Firefox allows users to enable or disable JavaScript on websites based on their preferences. JavaScript is a programming language commonly used to add interactivity to web pages, but it can also be used for malicious purposes. This feature aims to control users’ browsing experience and protect them from potential security threats.

Configure JavaScript Execution on Firefox browser

Nowadays, almost all browsers come with JavaScript(JS) support. It is a programming language web developers use to make their web pages more interactive by adding functionalities such as a menu, sounds, animations, and many other exciting features. Occasionally we might need to disable it due to security reasons.

Javascript is introduced to improve the user experience but has its demerits. The most common demerit of Javascript is advertising popups and other irrelevant information that needs to be closed.

A hacker also misuses it to hijack our browsers and inject malware. Disabling Javascript can solve numerous problems for you. It will also enhance browser security by eliminating the possibility of hijacking.

The major downside of disabling JavaScript is that it can break a site that is purely developed on it. You may also lose the interactive feature that JQuery(one of the JS libraries) has to offer.

Block Javascript

Javascript can sometimes cause your browser to lag due to its heavy nature and high processor requirement. By disabling JavaScript for the site, you can explore the simplified version of the webpage and fix your security issues.

Here are the steps to block JavaScript on Firefox:

  1. Launch the Firefox browser on the computer.
  2. Enter about:config command in the URL bar.
    How to block javascript on Firefox
  3.  Click on the Accept Risk and Continue buttons.
    How to block javascript on Firefox-2
  4. Lookup for javascript.enabled in the about:config search bar.
    How to block javascript on Firefox
  5. Click on Switch firefox-javascript-toggle the button to change the value to false.

This will disable JavaScript on your Firefox browser and will no longer be executed on any site. As mentioned, this will break the sites relying heavily on JS functions.

Allow JavaScript

Now if you have disabled the Javascript, then you might notice that certain websites may not be working. It’s expected behavior since these sites need JS execution in the backend to perform tasks. You have no other options except allow the JS to run on Firefox. Here are the steps to allow Javascript:

  1. Launch the Firefox browser on your computer.
  2. Enter about:config command in the URL bar.
    How to block javascript on Firefox
  3.  Click on the Accept Risk and Continue buttons.
    How to block javascript on Firefox-2
  4. Lookup for javascript.enabled in the about:config search bar.
    How to block javascript on Firefox
  5. Click the Switch firefox-javascript-toggle button to change the value to true.

Once you have made the changes, relaunch the Firefox browser and verify that JS is running and sites are no longer broken.

Bottom Line

You can disable Javascript to eliminate anonymous advertisements that ruin your browsing experience. It also helps in staying protected from digital hijackers.

However, a few websites won’t work if you have disabled the Javascript. So it is suggested that you allow Javascript before you browse those sites so they can load properly.

I wish Firefox might develop a robust option wherein we can manually allow or block the JavaScript execution on the sites.

What is your preferred option for JavaScript? Did you keep it enabled by default, or have you disabled it? What did make you change this option?

Lastly, if you've any thoughts or feedback on How to Allow or Block JavaScript in Firefox Computer, then feel free to drop in below comment box. You can also report the outdated information.

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Suresh Choudhary

Suresh has done a Master of Computer Application in Computer Science and has extensive knowledge of computer technology and application. He has 5+ years of experience in technical content writing and writing how-to tutorials. He uses Samsung Internet as the primary browser on his phone. Connect with Suresh on LinkedIn.

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