This report evaluates the website design principles of two popular ecommerce websites, Tesco and M&S, and compares them based on factors such as white space, accessibility, navigation, alignment, clarity, accuracy, consistency, content, and simplicity. It also analyzes the pros and cons of both websites in terms of usability, server side factors, and client side factors. Based on this analysis, the report suggests how Desklib, an online library for study material, can implement these website design principles to provide a better user experience.