PURPOSEBinge drinking (BD) is common among young people. E-Health apps are attractive to them and may be useful for enhancing awareness. We aimed to investigate the impact of a publicly available evidence-based e-Health app (Digital-Alcohol Risk Alertness Notifying Network for Adolescents and Young Adults [D-ARIANNA]), estimating current risk of BD by questions, matching identified risk factors, and providing in percent an overall risk score, accompanied by appropriate images showing mostly contributing factors in summary graphics.METHODSA natural, quasi-experimental, pre-/post-test study was conducted. Subjects were recruited in pubs, clubs, discos, or live music events. They were requested to self-administer D-ARIANNA and were re-evaluated after two further weeks.RESULTSYoung (18-24 years) people (N = 590) reported reduced BD at follow-up (18% vs. 37% at baseline). To exclude systematic errors involving those lost at follow-up (14%), the diminution in BD was confirmed in an appropriate generalized estimating equation model with unweighted data on a last observation carried forward basis.CONCLUSIONSOur study provides evidence of population-level benefit at 2 weeks, attained with D-ARIANNA. This can be disseminated easily and economically among young people. However, additional components, including regular feedback and repeated administration by gamification, may be required to make this app suitable for longer term impact.