This article presents part of the results of a study devoted to the assessment of Spanish pre-adolescents’ digital competences between the ages of 11 and 13. It is based on the implementation of a validated digital competences test designed to cover the five digital competence areas included in the European Digital Competence Framework called DIGCOMP, a common framework of reference on digital competence in Europe: information, communication, content creation, safety and problem solving. This study is focused on the competence area of safety, specifically on its analysis in relation to Spanish pre-adolescents and whether their results regarding this competence area are influenced by how frequently they use social media. Likewise, a conceptual approach to digital competence, its assessment, digital safety and use of social media in adolescence is also provided. The methodology describes how the test, which focuses on the area of safety, was administered to 595 pre-adolescents. The results show an average competence level in such area, which is insufficient considering current data on social media usage frequency. Besides, pre-adolescents who use social media moderately or do not use them at all display better digital competences in the area of safety in terms of knowledge, skills and attitudes.