Effects of four different extensions of the flat ΛCDM model on the sound horizon and the Hubble constant measured from the Planck data. The models considered here are ΛCDM + free N_eff, early dark energy, wCDM, and PEDE. The CMB-based constraints are compared to the measurements from late-time observations (SN + BAO + H0LiCOW + SH0ES/CCHP) shown with the grey shaded contours. The late-time measurements are obtained with model 3 (see Table 1) and show the 2σ credibility regions.