WASP-39b transmission spectra and calculations with different cloud mass load. Data are from JWST (orange), HST (magenta) and VLT (green) shown in comparison to Fe-free cloud scenarios with different cloud mass loads, ρ_g/ρ_d(z), in atmospheric layers where 〈a〉 < 0.1 μm (middle gray: 10⁻³ρ_g/ρ_d(z), dark gray: 10⁻²ρ_g/ρ_d(z), black: 0.1ρ_g/ρ_d(z)). The light gray line depicts the cloud-free case in the upper atmosphere. The models with Fe-free cloud materials and a reduced cloud mass load fit the whole wavelength range well.