The use of social networks has shown beneficial effects in the teaching-learning process, as well as highlighting its positive impact on student engagement and critical thinking. Likewise, integrating technology in higher education contributes to the developing of digital competence. However, it is still necessary to rethink the use of social media from a pedagogical viewpoint and from a transmedia perspective. The purpose of this study is to describe how an educational intervention with social networks, designed from a transmedia perspective, contributes to developing reflective and digital competencies of student-teachers. Participating in this study were 126 student-teachers. The results show that the intervention allowed high participation, was valued to be very satisfactorily, and it has turned out to be a facilitating element in terms of digital competence. Regarding the manifestation of critical thinking, most contributions were classified as superficial pre-reflections. More reflective training in needed to manifest a deep critical thought through the networks.