Forrester evaluated the grocery websites of four supermarkets in the UK — Asda, Sainsbury's, Tesco, and Waitrose —using its Website Functionality Benchmark methodology. We selected the four online grocery stores from those that are most frequently used and that have both an online and store presence. Overall, although none of the sites received a passing score on the Functionality Benchmark, there are areas where some sites excel. All of the sites scored well on purchase process functionality but were less advanced at merchandising capabilities. This report gives an overview of the successes and opportunities for improvement across the four sites.