Browser fingerprinting is a technique used to uniquely identify website users by collecting information about their devices and browsers, such as device model, operating system, and browser type, which is then combined to create a digital identifier known as a fingerprint. This method is particularly useful for detecting and preventing online fraud, such as unauthorized account access, by offering additional security measures like two-factor authentication when unfamiliar devices are detected. A detailed implementation using Node.js and Fingerprint Pro is described, which includes setting up a user registration system that limits sign-ups from the same browser within a certain timeframe, utilizing Express for web application creation, ejs for templates, and Sequelize for database management with SQLite. The system incorporates several validations to ensure the reliability of the generated fingerprints, such as verifying visitor IDs and checking time intervals to prevent replay attacks. The application also addresses challenges like bots detection and provides strategies for dealing with ad blockers that can interfere with the fingerprinting process. Browser fingerprinting is presented as a more persistent and effective method than cookies for user identification, especially in environments with stringent privacy settings.