The upsurge of ICT media and hybrid modalities for learning that stemmed from the world health crisis seem to be destined to stay. In this new paradigm, self-assessment processes have acquired an even more relevant role in the teaching learning process than they already had. Due to the myriad of academic online resources and information at their disposal and the normalization of online and hybrid systems of education, students need to know how to self-regulate their own learning more than ever. Self-assessment is one of the key instruments for the development of autonomous learning. This study presents the results of quantitative research conducted in a high school with EFL students in their last year of secondary education in Spain, where they wrote an essay that was assessed with a rubric. The study compares the results of self-assessment and teacher' assessment of an essay in an EFL classroom. In addition, students were surveyed on their insights of self-assessment with a rubric. The results demonstrate minor disparities between the evaluations conducted by the students and the teacher, as well as the favorable reaction of students towards self-assessment and their introspection concerning their own learning.