EcoTwin AI is an AI-powered sustainability platform developed as my submission for PromptWars 2024 – Challenge 3: Carbon Footprint Awareness Platform. The challenge required participants to design a solution that helps individuals understand, track, and reduce their carbon footprint through simple actions and personalized insights. To address this problem, I built EcoTwin AI, a personalized "Digital Carbon Twin" that transforms complex climate science into meaningful, everyday insights. Using verified emission factors and real-world datasets, the platform enables users to monitor activities across transportation, food, electricity, shopping, and waste while receiving AI-powered recommendations to make more sustainable choices. The application combines deterministic carbon calculations with Groq-powered AI guidance, future impact simulations, contribution tracking, live environmental insights, and interactive analytics to encourage long-term behavioral change and climate awareness.