This study analyzes urban expansion in three major Asian cities—Mumbai, Jakarta, and Hong Kong—between 2014 and 2024 using satellite-derived spatial indices. Four indices—NDVI, NDBI, BUI, and IBI—were applied to classify land cover and monitor annual changes in built-up and non-built-up areas. Six key metrics were used to track urban dynamics: built-up area, non built-up area, gain, loss, and overall change. Results indicate consistent urban growth across all cities, with Jakarta exhibiting the most significant expansion, while Hong Kong showed compact but steady development. In contrast, Mumbai revealed a surprising reversal in built-up trends, suggesting reclassification or partial vegetation recovery. The findings highlight varying urbanization patterns in South and Southeast Asia and underline the importance of spatial analysis for sustainable land-use planning. These insights contribute to a better understanding of coastal city dynamics and support evidence-based urban policy and planning.