Is JavaScript enabled by default in Firefox?

Yes, JavaScript is enabled by default in Mozilla Firefox. You only need to enable it if it was previously disabled.

Why does a page still say JavaScript is disabled after I enabled it?

Clear cache/cookies, check browser extensions that might block scripts, and verify Enhanced Tracking Protection settings.

How do I reset Firefox settings?

Type about:support in the address bar → Refresh Firefox button. This resets settings while keeping bookmarks and passwords.

Does Private Browsing affect JavaScript?

Global JavaScript settings apply in Private Browsing, but extensions and tracking protection may behave differently.

Where is the JavaScript setting on Android Firefox?

JavaScript is always enabled on Firefox for Android and cannot be disabled through settings.

How do I enable JavaScript on iPhone or iPad for Firefox?

On iOS/iPadOS: Settings → Safari → Advanced → JavaScript (applies to all WebKit browsers, including Firefox).

An extension says scripts are blocked. What should I do?

Disable NoScript, uBlock Origin, or similar extensions for the site, or add the site to their whitelist.

Will Enhanced Tracking Protection affect JavaScript?

JavaScript runs, but tracking scripts may be blocked. Try "Standard" protection or add the site to exceptions if needed.

How do I check if JavaScript is working?

Reload the page and verify interactivity. Open Web Console (F12) to check for script errors.

Enable JavaScript in Mozilla Firefox

Complete guide to enable JavaScript in Mozilla Firefox on desktop, Android, and iOS devices with step-by-step instructions.

Mozilla Firefox

Follow these steps to enable JavaScript in Mozilla Firefox on your computer, Android phone, or tablet.

Quick Navigation

Laptop / Computer Mobile Tablet FAQ

Laptop / Computer

Type about:config in the address bar and press Enter.
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Search for javascript.enabled.
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Double-click the preference to set it to true.
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Reload the page.
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Mobile

Tap the menu button (⋮) and select Settings.
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Go to Enhanced Tracking Protection.
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Tap Custom and ensure JavaScript is enabled.
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Reload the page.
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Tablet

Tap the menu button (⋮) and select Settings.
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Scroll down and tap Privacy & Security.
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Under Permissions, tap JavaScript.
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Toggle Enable JavaScript to enable it.
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Reload the page.
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Frequently Asked Questions

How do I enable JavaScript in Mozilla Firefox?

JavaScript is enabled by default in Firefox. If it's disabled:

Type 'about:config' in the address bar and press Enter
Click 'Accept the Risk and Continue'
Search for 'javascript.enabled'
If the value is 'false', click the toggle button to set it to 'true'

Note: Disabling JavaScript in Firefox affects all websites.

Can I enable JavaScript for specific sites only in Firefox?

Firefox doesn't have a built-in feature for per-site JavaScript control. However, you can use extensions like:

NoScript - Comprehensive script blocker
uBlock Origin - Ad blocker with script control

These extensions allow you to whitelist trusted sites while blocking JavaScript on others.

JavaScript is enabled in Firefox but some features don't work. Why?

This could be due to:

Browser extensions blocking scripts (check NoScript, uBlock Origin, or similar extensions)
Enhanced Tracking Protection blocking certain scripts
Outdated Firefox version
Corrupted cache or cookies

Try disabling extensions, clearing cache, or testing in Private Browsing mode.

Tips & Best Practices

Use Extensions for Control

Install NoScript or uBlock Origin to control JavaScript on a per-site basis. This gives you granular control over which sites can run scripts.

Enhanced Tracking Protection

Firefox's Enhanced Tracking Protection may block some scripts. If a site doesn't work, try adding it to exceptions in Settings → Privacy & Security.

Keep Firefox Updated

Always use the latest version of Firefox for the best security, performance, and JavaScript compatibility. Firefox updates automatically by default.

Use Web Console

Press F12 to open Developer Tools and check the Console tab for JavaScript errors. This helps troubleshoot issues with specific websites.

External Resources

About Mozilla Firefox

Learn more about Mozilla Firefox browser, its features, and development history.

Read on Wikipedia

About JavaScript

Discover the history, features, and importance of JavaScript programming language.

Read on Wikipedia