What Do Cookies Track?

Cookies serve as data packets exchanged between user browsers and website servers, enabling persistent tracking of user activity. The analysis confirms that cookies systematically record the following categories of information:

• Search history: Cookies log search queries, facilitating the personalization of content and advertisement targeting.
• Login credentials: Many platforms utilize cookies to store authentication tokens, thereby maintaining user sessions and reducing login friction.
• Shopping cart contents: E-commerce sites track items placed in virtual carts, allowing for session continuity across visits and devices.
• IP addresses: Cookies often pair with IP logging for geolocation, fraud prevention, and analytics purposes.
• Pages visited: Navigation paths are stored to analyze user engagement and optimize information architecture.
• In-page actions: Advanced tracking captures micro-interactions such as button clicks, mouse movements, and time spent per element, informing UI/UX decisions and behavioral analytics.

Empirical evidence shows that each cookie contains a unique identifier (ID), allowing servers to recognize returning users with high accuracy. This mechanism supports session management, content customization, and targeted advertising. Research highlights that third-party cookies extend this tracking across multiple domains, aggregating user profiles at scale (Mayer & Mitchell, 2012; Englehardt & Narayanan, 2016).

A comprehensive review of browser-server interactions demonstrates that cookies are inserted in HTTP headers and persist in local storage until expiration or manual deletion. Their use raises significant privacy concerns due to the breadth of data collected and potential for cross-site surveillance.