As research on sustainability orientation across generations is still sparse, we contribute to literature by enriching this research field, focusing on Generation Z (‘Zers’) and X (‘Xers’). Moreover, no other study has analyzed cross-generational differences in the sustainability context by making use of choice experiments, which overcome issues related to (Likert) scale item investigations, and allow respondents to evaluate the trade-off between different purchase factors simultaneously. We thus applied one of the most recent advancements in choice experiments, named Adaptive Choice-Based Conjoint analysis, which appears to be more realistic than previous alternatives. The results indicate Zers consume more sustainably (inter alia higher importance of social labels; higher purchase likelihood) when shopping online; however, differences within each generation were uncovered, especially among Xers (e.g., gender differences regarding importance of price).