Purpose This study investigates logistical challenges hindering sustainable online grocery retailing (SOGR) in Germany. It identifies critical factors for SOGR and improvement measures that interrelate these factors to strengthen economic, ecological and social sustainability simultaneously. An active-passive matrix determines the most impactful and receptive factors for cross-dimensional improvement.Design/methodology/approach Using a Grounded Theory approach, the study draws on fourteen semi-structured expert interviews. Sustainability challenges were coded into seven critical factors across the Triple Bottom Line (TBL). An active-passive matrix structures the recommended measures and illustrates their interrelationships across the three sustainability dimensions.Findings Optimized order picking, innovative food packaging, as well as punctuality and reliability emerged as the most impactful sustainability factors, each representing a different TBL dimension. The active-passive matrix shows how improvements in these factors generate positive effects across multiple other factors. Food waste was identified as having the greatest improvement potential. A previously unarticulated social factor (people's benefits) appeared during analysis, revealing latent impacts visible only through system-level evaluation.Practical implications The active-passive matrix offers retailers a practical tool to prioritize high-impact sustainability initiatives. By focusing on order picking, packaging and delivery punctuality and reliability, firms cannot only improve cost efficiency and reduce food waste but also enhance service quality, customer satisfaction and employee well-being. The findings highlight the importance of managing interdependencies across supply chain processes and offer guidance for different fulfillment models.Originality/value This study advances the literature by providing an integrated perspective on sustainability in online grocery retailing, linking economic, ecological and social dimensions within a single framework. It bridges home delivery and click-and-collect models, conceptualizes interactions between operational measures, and offers new insights from Germany's cost-sensitive market. By identifying leverage points that generate cross-dimensional synergies rather than trade-offs and distinguishing between the most impactful and most improvable factors, the study provides a more nuanced understanding of sustainability management in logistics-intensive retail contexts.