OBJECTIVE To validate, examine the internal validity, and adapt to children the electronic version of the composite cerebellar functional severity (CCFS) score. METHODS In this multicenter study, we compared the validated manual device with the new electronic version (n = 46) and analyzed its kinetics in 146 patients with Friedreich ataxia through the EFACTS (European Friedreich's Ataxia Consortium for Translational Studies) network, 77 patients with spinocerebellar ataxia, and 48 controls. We validated the CCFS in cerebellar ataxias in healthy children (n = 120) and children with Friedreich ataxia through the EFACTS network (n = 33). RESULTS We showed that the electronic CCFS is a reliable replacement for the manual version (intraclass correlation coefficient: 0.98 [0.97-0.99]), and that the electronic CCFS is consistent when performed several times (0.92 [0.84-0.97]). Analysis of kinetics data showed an acceleration and irregularity that is not relevant compared with total speed. The CCFS was tested after modification in a population of patients with Friedreich ataxia between 8 and 19 years old, and showed similar values as adult patients with Friedreich ataxia (1.203 ± 0.125 vs 1.228 ± 0.167) and significantly higher values than controls of the same age (0.863 ± 0.042). CONCLUSIONS The electronic CCFS is a quantified measurement of cerebellar ataxia independent of age, usable in individuals aged from 7 to 80 years. The automated nature of the electronic test device makes it reproducible between operators and centers, as well as easy to use.