This thesis presents FitTrack, a free fitness tracking web app built with the MERN stack. I developed it because existing fitness apps either charge for basic features or focus too much on social media rather than actual workout tracking. FitTrack lets users log workouts, visualize their progress with charts, and access video tutorials—all completely free. The biggest challenges were managing state with Redux, implementing secure authentication, and making the UI responsive across devices. The project successfully delivers an intuitive, accessible fitness solution that addresses real user needs.