Forrester evaluated the user experience at the Web sites of four leading UK online grocery retailers: Asda, Sainsbury's, Tesco, and Waitrose. Overall scores were above average, but no site passed our review. The most common usability flaws we uncovered included inefficient task flows, illegible text, hard-to-find privacy and security policies, and unclear category names. To improve the online user experiences they offer and differentiate themselves from competitors, UK grocers should fix known usability flaws and start to pilot next-generation online experiences that are more customized, aggregated, relevant, and social (CARS).