Yes, JavaScript is built-in and enabled by default. There are extensions that can block content, but I'm not seeing known content blocking extensions in your System Details. There is also built-in Enhanced Tracking Protection that can block content. ---- *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