PurposeEmergent research suggests that compulsive social media usage (CSMU) has a correlational link with well-being. Previous research in this area primarily focused on the prevalence, dynamics and consequences of social media usage. However, the knowledge of these occurrences among school and university students is still in its infancy stage. This research study addresses the knowledge gap by investigating the nexus between fear of missing out (FOMO), phubbing, CSMU and well-being.Design/methodology/approachCross-sectional surveys were conducted for collecting the data of school students and university students during COVID-19 when the exposure to the Internet and social media among the students had increased tremendously. Multivariate analysis and Moderated Mediated analysis techniques were performed to analyze the data using the structural equation modeling approach.FindingsThe results indicated that while on one side, students experience “FOMO”, on the other, they phone snub the individuals available to them to interact. FOMO significantly influences well-being; phubbing also has a significant impact on well-being; phubbing partially mediates the relationship between CSMU and well-being. However, for university students, the full mediation of phubbing in the relationship between CSMU and well-being was confirmed. It was also found that sleep fully mediated the relationship between CSMU and well-being.Originality/valueThis study provides novel highlights of the differential effects of FOMO, phubbing, sleep hygiene and well-being among the university and school-attending cohorts.