To compare the evolution of screen and Internet use by youths between 2012 and 2020 in Switzerland.Cross-sectional studies of 10th-graders (age 13-14) were performed in Switzerland in 2012 and 2020, and compared in bivariate and multivariate analyses on sociodemographic, schooling, physical activity, emotional well-being, and screen use variables.We found that screen use had shifted to smartphones with 71.7 % of youths primarily using this device in 2020 compared to 23.2 % in 2012. In association with this change, young people's screen time had increased dramatically with an odds ratio (OR) of 11.90 for adolescents spending more than 4 h in front of screens in 2020 compared to 2012. No changes were found in the score on the Internet Addiction Test (IAT) to detect problematic screen use and for adolescents' emotional well-being. Furthermore, youths in 2020 engaged in less physical activity lasting 60 min daily, but the frequency of their extracurricular sport participation remained unchanged.Young people spend more time on screens, especially because of an increase in smartphone use in 2020. However, youths do not seem to show more problematic behaviors regarding screen use, nor has this development affected their emotional well-being. The daily and continuous use of new devices is now an integral part of young people's lives. This process seems to be part of the growth of the digital world. However, Internet and screen addiction scales should be adapted to ensure that adolescents in need of help and counseling are identified.