“Knowing is one thing, doing is another". This paper addresses the gap between sustainability awareness and action by introducing MyEcoPal, a web application grounded in the Theory of Planned Behavior and Self-Determination Theory. MyEcoPal facilitates personal carbon footprint assessment, impact visualization, and the discovery of sustainable actions. The system utilizes an AI-Augmented Sustainable Action Framework to organize and evaluate 264 expert-curated actions. A user study revealed that MyEcoPal enhanced users’ understanding of their environmental impact and boosted engagement in planning sustainable behaviors, with many participants intending to continue these new habits. Users favored low-effort, high-impact actions, especially those related to Responsible Consumption and Clean Energy SDGs. These findings indicate that MyEcoPal’s strategy of linking motivation with visualized impact and personalized action plans is a promising method for encouraging sustainable practices.