themarkup.org
Blacklight is a real-time website privacy inspector from The Markup. A user enters a website address and Blacklight scans it, revealing user-tracking technologies on the site. Tests cover ad trackers, third-party cookies, tracking that evades cookie blockers, session-monitoring scripts, keystroke capturing, and data sent to Facebook, TikTok, Twitter/X and Google Analytics. A scan normally takes between 30 seconds and one minute.