heatmap.js is a JavaScript data visualization library used to render data density visualizations on a web page. It functions as an HTML5 canvas heatmap library that represents the intensity of data points across a coordinate system using color gradients.
The library provides tools for geospatial distribution mapping and user behavior analysis, such as mapping click patterns and interaction hotspots. It is also used to add visual intensity layers to interactive data dashboards to identify trends and anomalies.