This study investigated the factors influencing student engagement in asynchronous online classes, focusing on the roles of instructor presence, communication strategies, and demographic profiles. Data were collected from 385 college students employing moderated mediation with parallel mediators. The results revealed significant direct effects of instructor presence and communication strategies on student engagement, highlighting the pivotal role of these factors in shaping the online learning experience. Specifically, stronger instructor presence and effective communication strategies corresponded to higher levels of student engagement, emphasizing the importance of fostering supportive interactions and facilitating meaningful communication in virtual classrooms. Mediation analyses further clear the pathways through which these factors influence student engagement. Perceived instructional support emerged as a robust mediator between instructor presence and engagement, underscoring the significance of establishing a supportive learning environment. Additionally, technology self-efficacy played a modest yet significant role in mediating the impact of instructor presence and communication strategies on student engagement, highlighting the importance of students’ confidence in utilizing technology for academic purposes. While moderation analyses did not reveal significant effects of demographic profiles on the relationships between key variables, the findings underscore the universality of effective teaching practices in fostering student engagement across diverse student populations. These findings have important implications for online teaching practices and educational policies, emphasizing the need to prioritize strategies that enhance instructor support, foster effective communication, and promote technological proficiency among students. By addressing these factors, educators and institutions can optimize the online learning experience and promote meaningful engagement among students in asynchronous online classes.