Mass-density distribution of well-characterised giant planets. Left: planet bulk density as a function of planet mass for lightly irradiated (F_★ < 2 × 10⁸ erg s⁻¹ cm⁻²) giant planets (M_p > 0.1 M_J). Only well-characterised planets are shown, as in Fig. 18. The stellar metallicity is colour-coded, while the symbol size scales with insolation. The shaded green area corresponds to the mass-radius relation for giant planets in the absence of anomalous heating, i.e. assuming no inflation (from Thorngren 2024). Right: same plot, but for irradiated (F_★ > 2 × 10⁸ erg s⁻¹ cm⁻²) giants.