Sustainable consumption is increasingly shaped by online environments. Everyday exposure to online advertisement and social media content by peers may influence individual consumption decisions. By representative online surveys (N= 2,694), we examined how perception of online environments influences individual consumption levels of clothing, digital devices and leisure air travel, mediated by individual aspiration levels, personal and social norms. Structural equation modeling confirms relationships between perceived consumption-promoting online content and consumption levels, fully mediated through aspiration levels. Sufficiency-promoting online content is associated with higher social and personal norms for sufficiency, but neither of the latter are linked to aspiration or consumption levels. These findings are consistent with the hypothesis that aspiration levels and consumption decisions are influenced by consumption-promoting online content. Due to the use of cross-sectional data, it cannot be ruled out that these results reflect that more consumption-oriented individuals pay more attention to consumption-promoting online content. Hence, the dominant causal direction needs to be determined by experimental or longitudinal methods.