The Internet’s profound impact on society, communication, and the global economy is undeniable. Despite the studies on Internet adoption and frequency of use, little attention has been given to the intensity of usage as measured by the time spent online. In highly developed countries like the European ones, bridging the access gap is nowadays less relevant, as almost everyone has Internet access. Instead, the focus should be on analysing usage intensity to uncover new digital disparities among different groups and understand potential impacts on individuals' subjective well-being (SWB).This study aims to deeply examine Internet usage time, its socioeconomic determinants, and its effects on SWB using data from the European Social Survey (ESS) spanning from 2016 to 2020–22 in 21 European countries. We seek to answer two research questions: (1) How do individuals' characteristics influence Internet usage intensity? (2) What is the impact of Internet usage intensity on individuals' SWB?Our findings show inequalities in Internet usage time driven by individuals' socioeconomic and sociodemographic characteristics. Traditionally disadvantaged groups, both offline and online, exhibit lower Internet usage time, consistent with the existing literature on the digital divide. As for the effect of intensity of Internet use on SWB, after accounting for individuals' characteristics and addressing Internet's endogeneity, we found a negative and significant relationship between Internet usage intensity and life satisfaction, especially for the most intensive internet users.