Clustergrammer is a visualization library built using D3.js that enables intuitive interaction with high-dimensional data. Clustergrammer was built with biological data in mind. Clustergrammer is a web-based tool for visualizing high-dimensional data (e.g. a matrix) as an interactive and shareable hierarchically clustered heatmap. Clustergrammer's front end (Clustergrammer-JS) is built using D3.js and its back-end (Clustergrammer-PY) is built using Python.