The impact of filler interface on online users’ perceived waiting time Download delay, as a commonly experienced problem on the Internet, has become a significant impediment to the rapid development of online business. Extant researches focus on how such delays can be decreased and how much delay online users could put up with, but sparse study has adopted a theoretically grounded approach to managing the perception of the online wait. Some research results show that the reduction of perceived waiting time (PWT) involves filler interface, which includes diverseWeb design components such as images, music, text, progress bar, background color, or multimedia and so on. Based on resource allocation theory, cognitive absorption theory, we propose a conceptual model, design two different filler interfaces (pictures and music) and investigate their effects on antecedents of PWT. The research model considers cognitive absorption factors such as focused immersion, temporal dissociation, and heightened enjoyment as antecedents of PWT, which in turn affect users’ evaluations of Web sites.