The X Universal Website Tag (UWT) is a JavaScript snippet deployed on websites to enable comprehensive tracking of user behavior for advertising purposes. When loaded in a user's browser, it collects data on page views, specific actions (like purchases, sign-ups, or form submissions), and general website interactions. This data is then sent back to X's advertising platform. The primary function of the UWT is to measure the effectiveness of ad campaigns run on X by attributing conversions (e.g., a purchase or lead) back to specific ad clicks or views. It also facilitates the creation of custom audiences based on website visitors, allowing advertisers to retarget users who have shown interest in their products or services, or to exclude existing customers from certain campaigns. The script operates by setting and reading cookies to identify unique users and sessions, ensuring consistent tracking across visits. It sends collected data to X's servers, which process it to provide analytics and power advertising features.