The purpose of research is to identify the challenges and opportunities of government’s digital diplomacy effectiveness assessment. The authors review the up-to-date studies of digital diplomacy effectiveness assessment, generalize the international experience in the evaluation and practical implementation of digital diplomacy, as well as develop the proposals on indicators and criteria of digital diplomacy effectiveness assessment. The authors consider the effectiveness of digital diplomacy on three different levels: the level of information delivered to foreign audience, the level of influence, and the level of interaction with the foreign audience. The authors find out that foreign policy strategies of leading powers do not contain references to the criteria for digital diplomacy effectiveness, with the exception of the United States. Therefore, the authors have attempted to develop such criteria and constraints that need to be discussed.