Background: Well-being is crucial for children's and adolescents' mental health. Despite numerous interventions, innovative technological options are still underexplored, particularly for younger populations. This study aims to review, summarize, and discuss experimental studies on the effects of technological interventions on well-being in childhood and adolescence. Method: We conducted a systematic review and meta-analysis following PRISMA guidelines, including studies published since 2013. Searches were conducted in PubMed, PsycInfo, Scopus, and Web of Science including randomized and non-randomized controlled trials. The quality of studies was assessed using the Cochrane Risk of Bias (ROB-2) and ROBINS-I tools. Meta-analyses were performed using R studio. Results: Of the 2705 articles screened by title and abstract, 55 underwent full-text review. Seventeen articles were included, showing a diversity of technology-based interventions, including apps, web-based intervention, digital intervention, and chatbots. The meta-analysis (n = 5636 participants) showed a small but statistically significant effect in promoting well-being (Hedges's g = 0.18; p < .01). App-based interventions demonstrated a notably larger effect size (Hedges's g = 0.33; p < .001). Conclusions: The findings highlight a range of technological interventions for promoting well-being in children and adolescents, with apps showing greater effectiveness. This supports their use as valuable resources for this population..