JavaScript is a built-in component and is enabled by default. If a website complains that JavaScript in disabled then this is usually caused by a content blocking extension you have installed. Another possibility could be Enhanced Tracking Protection in Firefox. *https://support.mozilla.org/en-US/kb/enhanced-tracking-protection-firefox-desktop *https://support.mozilla.org/en-US/kb/total-cookie-protection-and-website-breakage-faq *https://support.mozilla.org/en-US/kb/trackers-and-scripts-firefox-blocks-enhanced-track