How to disable JavaS­cript in Firefox, Chrome and Edge

With step-by-step in­struc­tions, we’ll explain how to disable JavaS­cript in Mozilla Firefox, Google Chrome and Microsoft Edge. We’ll also take a look at different security risks as­so­ci­ated with disabling the scripting language.

How do you disable JavaS­cript in browsers?

All popular web browsers offer the pos­sib­il­ity to disable JavaS­cript. The location of this feature varies from browser to browser. We’ll explain below how to disable JavaS­cript in Mozilla Firefox, Google Chrome and Microsoft Edge. All it takes is just a few clicks.

How to disable JavaS­cript in Firefox

If you want to disable JavaS­cript in Firefox, you need to use the con­fig­ur­a­tion editor. While prior to version 23, users could disable JavaS­cript in the browser settings, this option is no longer available. To disable JavaS­cript in Firefox, follow the steps below:

Step 1: Enter about:config in the address line and press Enter.

Step 2: If you are opening the con­fig­ur­a­tion editor for the first time, Firefox will show the following warning before re­dir­ect­ing you. Click Accept the Risk and Continue to access the con­fig­ur­a­tion settings.

Step 3: Enter javascript.enabled into the con­fig­ur­a­tion editor search bar. Firefox will auto­mat­ic­ally filter the line you want from the rest of the settings. Click on the toggle switch to change the value of the setting from true to false.

How to disable JavaS­cript in Chrome

Google Chrome users can manage JavaS­cript options directly in their browser settings.

Step 1: Click on the menu icon (three points) in the upper right corner of your browser window and select Settings to open the browser settings.

Step 2: Click on Privacy and security in the menu on the left and then on Site settings.

Step 3: Scroll down to the section labelled Content and then click on JavaS­cript.

Step 4: In Chrome, JavaS­cript is auto­mat­ic­ally enabled. If you to want to disable JavaS­cript for all websites, choose the option Don’t allow sites to use JavaS­cript. You also have the option to disable or enable JavaS­cript for certain sites in the section labelled Cus­tom­ized behaviors.

How to disable JavaS­cript in Microsoft Edge

Microsoft offers Edge users the option to stop the client-side execution of scripts. You can disable JavaS­cript in the Edge browser settings by following the steps below:

Step 1: Go to the general menu of Edge (three-dot icon) and select the menu item Settings.

Step 2: In the left sidebar menu, click on Cookies and Site Per­mis­sions and scroll down to the All Per­mis­sions section. Here, you’ll find the entry JavaS­cript. Select this option.

Step 3: Move the toggle switch in the Allowed (re­com­men­ded) line to the left to disable JavaS­cript in Edge. You can also enable or disable the scripting language for in­di­vidu­al websites by creating an entry in the allow list (to enable) or block list (to disable).

What effect does disabling JavaS­cript have on websites?

Before you disable JavaS­cript in your web browser, you should be aware of the con­sequences. According to w3techs.com, ap­prox­im­ately 99% of web pages on the internet use the scripting language. Often, these pages can only be displayed correctly if your web browser is able to process JavaS­cript.

It’s also important to keep in mind that not all websites have al­tern­at­ive versions that can function without scripts. If you disable JavaS­cript, you run the risk of missing out on essential content.

What risks does JavaS­cript pose?

Alongside HTML and CSS, JavaS­cript is one of the standard tech­no­lo­gies of the web. Client-side pro­gram­ming is in­dis­pens­able in modern web de­vel­op­ment and can be found every­where on the internet. However, it’s important to be aware of the risks as­so­ci­ated with JavaS­cript.

In essence, JavaS­cript is a pro­gram­ming language with very limited per­mis­sions. The scripting language allows you to:

• ma­nip­u­late your current browser window using DOM (Document Object Model)
• open new browser or dialog windows
• animate, show, hide or modify page elements
• validate input values
• load Ajax content
• transmit in­form­a­tion about the user’s reading habits and browsing activ­it­ies to other websites

JavaS­cript only has access to users’ cookies and other data storage that is des­ig­nated for websites. JavaS­cript does not have access to users’ hard drives, so it is unable to call libraries or launch ad­di­tion­al programs on the computer. These lim­it­a­tions are enforced by the sandbox principle, which confines the impact of scripts to the browser window where JavaS­cript is being executed.

Despite these lim­it­a­tions, JavaS­cript can still be ma­nip­u­lated. The scripting language can be misused to:

• extract in­form­a­tion about the browser or operating system in order to track user behaviour or exploit security vul­ner­ab­il­it­ies (such as outdated plugins)
• open numerous pop-up windows to overwhelm a user’s computer (known as Denial of Service, or DoS)
• conceal malicious code
• mimic websites from trusted providers as part of a phishing attack

In addition, pro­gram­ming errors may only become apparent when a script is executed on a user’s computer.

The primary security risk, however, has less to do with the scripting language itself and more with the specific JavaS­cript in­ter­pret­er used within a browser. If an in­ter­pret­er contains flaws, this can lead to security vul­ner­ab­il­it­ies that need to be dealt with quickly. Only by doing so, can you be sure that scripts are operating in isolation in a sandbox en­vir­on­ment and aren’t able to impact other programs or the core system.