This study aims to compensate for the shortcomings of the adaptive web of the Musinsa platform website, which has the highest percentage of MZ generation consumers in the fashion e-commerce platform market. Thus, the purpose of this study is to develop a responsive web that reacts fluidly to various devices and considers the user's purchase experience. The research method examines the concepts and features of the responsive and adaptive designs and theoretically examines the five responsive layouts defined by Luke Wroblewski. The characteristics of Musinsa, built with adaptive design, were analyzed by analyzing the websites of fashion platforms using responsive design. Based on the analysis results, a prototype was constructed through wireframe design, and a responsive web was designed. The conclusion of this study is as follows. Musinsa is a fashion commerce platform that provides fashion content and an online shopping mall. Therefore, This study designs and proposes a responsive web that can provide consistent purchasing and content experiences on various devices, rather than an adaptive web with limitations in exposing the platform's core value and poor user experience regarding device fluidity. The responsive web of Musinsa, designed and developed in this study, is designed to expose various contents by fluid layout and media rules and to make efficient information access by utilizing their characteristics and changing expression methods as necessary. The results of this study can further activate the web of Musinsa to improve users' purchasing experience and ultimately expect a positive effect of sales increase.