A bstract – Abstract – Optic King was established in July 2022 , operating in the optical sales sector. Currently, Optic King still employs a face-to-face sales method, where buyers need to visit the store to make eyewear purchases. The challenges include delays in writing eyewear prescriptions and sales receipts, as well as the manual processing of sales data. This manual approach often leads to errors such as lost, misplaced, or damaged eyewear prescriptions and receipts due to inaccuracies in transaction recording. The store owner faces difficulty in monitoring transactions in the business. The purpose of this research is to design the user interface and user experience for website application to facilitate the buying and selling system. The method employed in this research is the Human-Centered Design (HCD) method. The Human CenteredDesign (HCD) method consists of five steps: understanding and determining the context of use, determining user needs, generating design solutions, and evaluating design solutions. In testing the design using the System Usability Scale (SUS), the prototype of the web-based application at Optic King. Optic King received a SUS score of 86,83 which rating as \"Best Imaginable\" category. Based on the results of the research that has been carried out, it can be concluded that website application for Optic King has succeeded in building a system with a good level of usability.