Because of the increasing popularity of mobile Internet access, web pages that provide priority for mobile first are gradually leading the field of web design. Therefore, Responsive Web Design (RWD), which is designed to respond to different devices, has become the mainstream of current web design. Based on this trend, this study will compare responsive web pages on computers and smart phones and evaluate their visual design and user interface. This study is divided into two phases. First, this study used an independent sample t-test. The independent variable is the ＂responsive interface＂ of web stimuli on different devices. The dependent variable is the ＂web design assessment＂ indicator that is synthesized from the literature. In the second phase, this study used regression analysis to explore the state of association between the overall evaluation and each subproject. This study summarizes three conclusions that can be used as a reference for optimizing Responsive Web Design (RWD) design. First of all, as far as visual design is concerned, when users use a desktop computer to browse a responsive website, the beauty and consistency they feel will be better than using a smart phone. But in terms of comfort, there is no significant difference. The second is that although the users have positive comments on the smoothness, feedback and ease of use of the responsive website on the desktop and mobile phones, the difference between the two devices has not been significant. Finally, in terms of the overall evaluation of the responsive website, users pay more attention to the aesthetic factors in visual design, and the ease of use and feedback of interface operations.