Comparison between constraints on r_d and H₀ from the full Planck likelihood (dashed lines) and the compressed likelihood (for post-recombination modifications of ΛCDM) or the extended compressed likelihood (for pre-recombination modifications of ΛCDM) used in this study (solid lines). The robustness test comprises two cases: the standard flat ΛCDM model and its extension with a free number of neutrinos.