Abstract Background eHealth literacy is a necessary competency for individuals to achieve health self-management in the digital age, and the evaluation of eHealth literacy is an important foundation for clarifying individual eHealth literacy levels and implementing eHealth behavior interventions. Objective This study reviews the research progress of eHealth literacy assessment instruments to offer suggestions for further development and improvement as well as to provide a reference to eHealth intervention. Methods We reviewed papers on Web of Science, Scopus, PubMed, and EBSCO in English between 2006 and 2024 and included studies involving the development of eHealth literacy assessment instruments, which must be published in peer-reviewed journals. An analysis in terms of the development process, instrument characteristics, and assessment themes was conducted to reveal the content, features, and application of currently available eHealth literacy assessment instruments. Results Searches yielded 2972 studies, of which 13 studies were included in the final analysis. The analysis of the 13 studies indicated that the development of instruments is improving constantly, as the concept of eHealth literacy evolves. In total, 9 of the 13 tools are subjective assessments, with eHealth Literacy Scale being the most widely used. In contrast, the remaining 4 comprehensive assessment tools incorporate objective evaluation criteria. The 13 instruments’ reliability ranged from 0.52 to 0.976. Validity was reported for 12 tools (excluding eHealth Literacy Scale), covering 5 types: content validity, structural validity, discriminant validity, external validity, and convergent validity. Regarding assessment themes, skill factors are involved in many instruments, but psychology factors and information factors are less concerned. Conclusions The evaluation of the characteristics of existing eHealth literacy assessment tools in this paper can provide a reference for the selection of assessment tools. Overall, subjective and comprehensive assessment tools for eHealth literacy have their own advantages and disadvantages. Subjective assessment tools have a friendly evaluation method, but their test validity is relatively low. There is a risk of time-consuming and low recognition for comprehensive evaluation tools. Future research should be based on the deepening of eHealth literacy connotation, further verifying the effectiveness of existing eHealth literacy assessment tools and adding objective evaluation dimensions.