Fingerprinting is a technique used to identify website users by analyzing device or browser settings, such as fonts, operating system, and hardware information, to create a unique pattern. While it has been criticized for potential privacy violations, fingerprinting serves legitimate purposes like fraud detection and distinguishing bots from humans. This method is particularly useful for preventing activities like credential stuffing by verifying if a fingerprint is genuine. The article provides a detailed guide on integrating fingerprinting into a React application for fraud detection using Fingerprint's React SDK and Node.js for server-side validations. It outlines steps for setting up a React app, registering user fingerprints, and performing validations during user sign-up and login to ensure secure authentication. Fingerprinting offers advantages over cookies and IP tracking by being harder to spoof and effective even in incognito mode, making it a reliable tool for detecting suspicious activity without relying on browser storage. The tutorial demonstrates how this technique can enhance security by preventing sign-up fraud and offers a free trial for users to explore Fingerprint's offerings.