Objective A visible difference in appearance caused by a congenital or acquired condition can negatively affect adolescents’ psychosocial well-being. Young Person's Face IT (YPF) is an online intervention based on cognitive behavioural therapy and social skills training, developed to help adolescents who struggle with adjusting to a visible difference. The objective of the present study was to explore adolescents’ and parents’ perceptions of the intervention's relevance and usefulness in supporting young people with appearance-related psychosocial concerns. Methods Participants were adolescents ( N = 76, aged 11–18) and parents ( N = 15), recruited in a larger randomised controlled trial aiming at evaluating YPF. This qualitative study with descriptive data includes adolescents’ ratings on YPF's usefulness, and interview data from adolescents and parents on their experiences with YPF. The interviews were analysed using a thematic approach. Results Results indicated that YPF was experienced as useful and relevant. Interviews showed that adolescents felt validated through the programme's content, discovered that other young people had similar experiences and felt that YPF could contribute to changing self-perceptions for the better. However, results could not confirm whether perceived usefulness led to the development and use of new social skills in real-life situations. Conclusion This study offers new perspectives on the relevance and usefulness of YPF in supporting adolescents with appearance-related psychosocial concerns. Findings suggest that updates and modifications are required so that YPF stays relevant and useful for adolescents in need of support. Trial registration number NCT03165331