This study provides an analytical approach to using collaborative heatmaps from Instasights to gain an insight on the impact of renewed waterfront urban areas in terms of their relevant role in the perceived functional dynamism and livability of the city. The proposed method enables the identification of perceived functional thematic areas—districts, as Kevin Lynch would refer to them in his work ‘The Image of the City’—based on user-generated social media data, although the method adopted in this study diverges from that of Lynch, which is based on fieldwork. Instasights is used as a research tool because the demo app collects, analyzes and visualizes data from a vast amount of social media. Five waterfront Spanish cities—Madrid, Barcelona, Valencia, Bilbao and Zaragoza—have been... selected as case studies to validate the method used. The main novelty of the study is the possibility of monitoring urban environments, even though they may be perceived as several thematic areas. The findings suggest that the proposed method is a valuable tool for gauging the pulse of waterfront areas through Instasight heatmaps. Moreover, differences in the way renewed public spaces are used and perceived, as well as overlapping functional areas are identified in the case study cities. The approach taken in this study provides a deeper understanding of the perception and complex dynamism related to the monitoring of the waterfront post-renewal phase, which enhances the study of urban renewal.