Studies promote crowdsourcing as an alternative source of creativity for companies. By investigating whether a boundary exists in crowdsourcing for innovation, we aim to identify the conditions under which the generic crowd (mainly consisting of novices, instead of professionals) is less creative. Based on the componential theory of creativity, we compare the crowd’s and professionals’ creativity, focusing on generalist versus specialist tasks. Leveraging online experiments and semantic analysis, we find that the crowd is more creative than professionals in solving generalist tasks. However, the crowd is less innovative than professionals in solving specialist tasks, thereby suggesting a boundary to crowdsourcing. Nevertheless, to solve specialist tasks, members of the crowd can gain relevant knowledge by exposing themselves to each other’s ideas, thereby suggesting an attempt to break the boundary. This study offers new insights into the boundary of crowdsourcing for innovation.