Gender disparities in digital literacy (DL) are a well-documented phenomenon across diverse developmental stages and socio-cultural contexts, yet they remain inadequately addressed in DL education. A potential underlying reason may lie in the measurement approaches employed, as self-reported measures are susceptible to bias and may not accurately reflect actual DL performance. Therefore, this systematic and meta-analytic review investigates gender disparities in performance-based DL and its developmental trajectory from Grade 3 to Grade 12 by synthesizing empirical evidence from 43 studies across 31 regions since 2005. Notably, the Gender Inequality Index was intentionally incorporated to examine the interplay between DL and socio-cultural contexts. The analysis adopted a mixed-method approach, integrating thematic and content analysis with the meta-analysis under the Bayesian framework — chosen for its robustness to small sample sizes and capacity to incorporate prior information. The cross-sectional meta-analysis revealed a consistent girl advantage (k = 67, g = +0.14, 95% CI[0.11, 0.18]). However, the longitudinal meta-analysis (k = 6) showed comparable growth rates for girls (d = 1.48, p < .001) and boys (d = 1.29, p < .001). Triangulated qualitative findings revealed that gender differences were most pronounced in upper primary and lower secondary education and were unexpectedly larger in highly developed regions than in developing ones. These findings contradict the gender stratification theory, which predicts smaller disparities in more gender-equal societies. Instead, they support the gender-equality paradox, suggesting that socio-cultural and developmental factors interact to shape DL outcomes. Methodological variations such as test modality and psychometric modeling were also identified as sources of inconsistencies across studies. This review extends traditional gender difference theories into the domain of DL education. It underscores the urgent need for international collaboration in research and pedagogical reform to promote gender equality in DL education, thereby fostering equitable career opportunities and advancing human well-being.