The aim of the study is to explore whether and how WhatsApp interactions can improve students' psychological well-being by focusing on the mediating role of bonding social capital (BOC) and bridging social capital (BRC). The present study also investigates the moderating role of social integration in association with WhatsApp use and psychological student well-being. Data were collected from 266 college and university students from Islamabad, Pakistan. Results showed that time spent on WhatsApp positively influenced student psychological well-being and that social integration significantly affected the mediation of BOC in association with WhatsApp use and student psychological well-being but insignificantly affected the mediation effect of BRC in association with WhatsApp use and student psychological well-being. The study also discusses the implications and future directions. •Time spent on WhatsApp has significant positive affect on student's PSW.•WhatsApp usage strengthened the bonding social capital of students.•Social integration moderated the mediation of bonding social capital