Purpose: This study aimed to illustrate upper secondary school pupils’ experience using a self-administered web-based health-promoting tool, the Swedish Physical Power, Mental Harmony, and Social Capacity (FMS) student profile. Method: Five upper secondary schools in Sweden were included. Focus group interviews with pupils (10 girls, 5 boys, 15–19 years) were conducted, and data were analyzed using qualitative content analysis. Result: Two themes were generated from six categories: a sense of participation and self-control of health: everyday well-being, objective formulation, disappointment, health awareness, limitations, and health-promoting change. The participants experienced that using the FMS made them aware of factors that influence their health. They also reported that being given feedback visually from the FMS, peers, and staff involved in the school was beneficial in increasing their motivation to maintain a health-promoting change regarding physical activity and lifestyle factors. Conclusion: The use of a self-administered web-based health-promoting tool is viewed as beneficial for raising awareness and motivation to implement strategies that help attain a healthier lifestyle in upper secondary school students regarding factors affecting perceived health.