In today's ‘always-connected’ world, people spend hours online using their smartphones. This study contributes to ongoing debates examining how smartphone use and smartphone use experience relate to life satisfaction. We distinguish smartphone use by purpose and timing, and we are interested in how individuals experience this use (their online vigilance and smartphone well-being). Combining information on use and experience allows us to examine both their associations with life satisfaction and how the link with smartphone use varies depending on the user's experience. Using data from 2259 adults in Flanders, the analysis also considers heterogeneity across socio-economic groups. Findings show that the relationship between smartphone use and life satisfaction depends on both the type and timing of use. Social media use is more negatively associated with life satisfaction than communication app use, particularly during non-work periods. Smartphone use experience is negatively associated with life satisfaction at the bivariate level, but these associations largely disappear once usage patterns are accounted for. This finding suggests that experiences are closely intertwined with how smartphones are used. Moreover, smartphone use experience primarily acts as a moderator, shaping whether smartphone use is associated with more positive or negative outcomes. We observe heterogeneity across socio-economic groups, with more complex patterns among students and more limited associations among employed and non-active individuals. Overall, the findings highlight the ambivalent and context-dependent nature of smartphone use in relation to life satisfaction.