Mass–radius relation of observed exoplanets. Planets in green are potentially inflated by past or ongoing rainout, in comparison to planets that formed with core-envelope structures. The rainout effect on the inferred H,He mass of the marked exoplanets is shown in Table 1. The sub-Neptune planets with radii above 3.3 R_⊕ that aren’t marked in green lack an age measurement and are thus not included in our analysis. Planets with radii below 3.3 M_⊕ are consistent with low (< 5%) H,He and thus rainout has negligible effect on radius at Gyrs age.