The growing use of smartphones has been pointed out as one of the main reasons for the decrease in children’s outdoor time. However, there is still a gap in our understanding of how smartphone use affects children’s outdoor experiences and activities. The aim of the study is to explore children’s dependency on their smartphones, what smartphone functions children use when outdoors and how smartphone use affects children’s outdoor experiences. The study uses a mixed methods design which implements interviews with a small sample of children (N = 34) in order to help develop a questionnaire for a larger sample (N = 1148). Both datasets are included in the analysis with a complimentary perspective. The results suggest that children are highly dependent on having their smartphones available as an integrated part of their lives. However, smartphones also create favorable conditions for rich and valuable outdoor lives by expanding children’s and parents’ sense of security, children’s outdoor sociality, and children’s opportunities to mold their outdoor experiences. We stress that children’s passion for the digital world needs to be reconsidered as not ‘all bad’, but more as a condition in modern children’s lives and an asset to embrace in future strategies for actively engaging children in outdoor activities.

School recess provides a unique opportunity for children to be active. However, many children perceive smartphones as a key barrier for engaging in physical activity during recess. The aim was to investigate if a ban on smartphone usage during recess changed children’s physical activity. During August–October 2020, children from grades 4–7 (10–14 years) at six Danish schools were banned from using their smartphones during recess for a four-week period. Questionnaire and systematic observation (SOPLAY) data were collected from 814 children before intervention (baseline) and 828 during the last week of intervention (follow-up). The mean frequency of physical activity significantly increased from baseline to follow-up (odds ratio = 1.370), as did physical activity on a moderate level (odds ratio = 1.387). Vigorous physical activity significantly decreased (odds ratio = 0.851). The increase in physical activity was found among both schools having outdoor and indoor recess, among both boys and girls, and nearly equally among grades 4–7. This suggests that implementing a ban on smartphone usage during recess would improve the everyday conditions for health among a broad range of schoolchildren. Future studies are needed to further investigate the association between recess physical activity and smartphone usage.