Abstract: As digital technologies become deeply embedded in everyday life, users face data visibility and social visibility at the same time. Weibo’s public information aggregation and Xiaohongshu’s sharing of lived experiences engender differentiated rules of visibility. In the dimension of data visibility, platforms leverage the principle of connectedness to guide users in producing behavioral data through autonomous, passive, and pseudo-selective sharing, ultimately achieving commercial monetization through the principle of connectivity. Ambiguous privacy agreements and default public settings make it difficult for users to notice how far their data are visible. In the dimension of social visibility, mutual watching within circles is internalized by youth as a social culture, whereas tracking across different circles and platforms, coupled with the intrusion of offline relationships, frequently precipitates context collapse. Furthermore, Weibo commodifies the visibility of viewing behaviors, intensifying the strategic maneuvering over visibility among users. Confronted with dual visibility, youth develop strategies to reconstruct social boundaries and reshape their digital personas. However, constrained by technological regulation and deep social embeddedness, the efficacy of their adjustments remains limited. This study offers valuable insights for understanding youth digital practices and platform governance.