Along with the development of information technology and artificial intelligence, online knowledge sharing has become an essential organizational resource. Online knowledge sharing can contribute to the success of organizations through effective knowledge management which is often enhanced by using artificial intelligence techniques. Young employees often make up the largest segment in organizations, but they tend to start their early career with temporary contracts which impact their likelihood to hide or hoard organizational knowledge. This study examines knowledge self-efficacy, perceived ease of use, organizational rewards, and top management support affecting the online knowledge sharing capability of young employees. A survey was conducted in Vietnam, targeting young employees aged 18–30 in three key industries. Results indicate that knowledge self-efficacy, perceived ease of use, and top management support significantly influence young employees’ online knowledge sharing. Interestingly, organizational rewards were found to only impact lurkers’ online knowledge sharing and work effectively if employees have either high perceived ease of use or top management support.