Radius–density data from the PlanetS catalog and the derived relation. Top: radius-density distribution of all exoplanets from the PlanetS Catalog. Bottom: the exoplanets from the PlanetS Catalog smaller than 7 R_⊕ are displayed together with the mass–density relation (solid black line) and the corresponding breakpoints (dashed line). The light-shaded areas are the 1σ-uncertainties.