The ability to use digital technologies effectively is unevenly distributed among adolescents. Youths from lower socioeconomic backgrounds, girls, and migrants frequently exhibit lower digital competencies, which can contribute to long-term educational and occupational disadvantages. To design educational strategies that promote digital equity, it is essential to understand when and for whom these inequalities emerge. This longitudinal study examined the development of social, gender, and migration-related disparities in digital competencies during adolescence. Using data from the German National Educational Panel Study (N = 4872), we examined digital competencies that were assessed three times between ages 12 and 18 with standardized achievement tests. Latent growth curve analyses revealed distinct developmental patterns: socioeconomic disparities were initially large (Cohen's d = −0.22) but decreased over time (Cohen's d = −0.16); gender differences favoring boys were small at first (Cohen's d = 0.07) but widened during adolescence (Cohen's d = 0.18); and the migrant gap was already substantial in early adolescence (Cohen's d = −0.18) and remained stable later on. Comparative analyses for math and reading literacy highlighted partial parallels between digital inequalities and traditional educational inequalities. Overall, the results indicated persistent social, gender, and migration-related disparities in digital competencies throughout adolescence. Because these gaps remained considerable in later adolescence, they appear insufficiently addressed by the current educational system. To reduce digital inequalities, educational interventions may need to begin even before adolescence and target younger children in order to prevent disparities from becoming firmly established.