In the didactics of higher education, the issue of teacher training for the use of end-to-end digital technologies in professional activities, defined as the formation of end-to-end digital competencies, remains insufficiently investigated. The structure and content of these competencies is the subject of scientific debate. Building models of teachers' digital competencies is necessary to ensure the processes of digital transformation in educational organizations. To design a methodical teacher training system for the use of end-to-end digital technologies, it is necessary to determine the planned results and develop tools to diagnose their achievement. The purpose of the study is to describe a methodology for diagnosing the level of formation of end–to-end digital competencies of students - future teachers. The research was carried out on the basis of a competence-based approach, the structure of digital competencies was considered as a set of three components: cognitive (knowledge), activity-based (skill), integrative (practical experience). To substantiate the elements of the content and levels of formation of end-to-end digital competencies, a bibliometric network analysis of publications on the research problem and the method of group expert assessments with the involvement of university professors and current teachers as experts were used. Results. In the course of the research, a codifier of the verifiable elements of the content of teacher training for the use of end-to-end technologies in professional activities was developed, the structure of end-to-end digital competence in the field of a certain digital technology was described, and the levels of its formation were determined. The created diagnostic tools were used during the All-Russian Distance Olympiad on end-to-end technologies in education for bachelors and masters of pedagogical education. The research materials can be used in designing the content of modules and disciplines of teacher training curricula.