Understanding how a city operates has never required full immersion on foot or hours of people-watching from a bench outside a train station. These days, real-time data and digital platforms do most of the legwork. Anyone can read the flow of a city by observing its online signals, which move as rapidly as traffic during rush hour. Location-based apps, social feeds, open data portals, and maps with live overlays create an ongoing narrative of urban behavior. Individuals can use this information to understand how people move, where they gather, and what draws their attention at particular times.