In order to improve website usability, it is important for developers to understand how users access websites. In this paper, we present Webjig, which is a support system for website usability evaluation in order to resolve the problems associated with the existing systems. Webjig can collect users' interaction data from static and dynamic websites. Moreover, by using Webjig, developers can precisely identify users' activities on websites. By performing an experiment to evaluate the usefulness of Webjig, we have confirmed that developers could effectively improve website usability.