Large-scale interaction network visualization of biochemical molecules, such as genes, proteins, or drugs, to understand complex biological systems is a common technique in modern biology. Simple visualization of interactions with node-link diagram is not scalable and tends to fall into so-called “hairball problem.” To resolve this issue, we developed a web-based network browser called HiView. It takes hierarchies generated by various clustering and community detection algorithms and displays it as a circle packing diagram. Users can browse the complex interaction networks using the visualized hierarchy as a guide to understand the subsystems in the biological networks. It also works as an information dashboard to integrate known biological functions of the genes and subsystems using external public biological databases.