The UK's definitive supermarket survey reveals the best grocery stores and websites, as well as those you might want to avoid.
Supermarkets compete fiercely for customers, and it's getting harder than ever to know which ones have the best deals, offer great-quality food, and give you five-star service to boot.
So to bring you the definitive answer on where to shop depending on whether you prioritise value for money, a pleasant in-store experience or all-round great service, we asked 14,049 shoppers what they really think of their supermarket and gave each of the big players a score.
In the tables below, we've rated all of the major supermarkets, from giants such as Tesco and Sainsbury's to discounters Aldi and Lidl. We've also compared online-only grocer Ocado with the web and app offerings of traditional supermarkets such as Asda and Waitrose to see which online supermarket gives you the freshest produce, most convenient delivery slots and friendliest drivers.
Only logged-in Which? members can view the exclusive supermarket review results in the tables below.
Best supermarkets for shopping in-store
Best supermarkets for shopping online
How do we find the UK's best and worst supermarkets?
We surveyed 14,049 Which? members in September and October 2019 for our annual supermarkets survey. The respondents were only asked about supermarkets they had shopped in.
For those who do their supermarket shopping in-store, we asked them to rate how good the supermarket looks and how long it takes to queue at the checkout. We also asked whether there are friendly staff available to help with any queries.
For online shoppers, we asked whether there's usually a good choice of delivery time slots, whether the supermarket chooses sensible substitutions when items are unavailable, and how good the drivers' service is.
We asked both in-store and online shoppers all-important questions about the value for money on offer at their chosen supermarket and the quality of fresh and own-label products.
And finally, we asked how satisfied shoppers are on the whole with their supermarket, and whether they would recommend it - these two questions allow us to calculate our unique Which? customer scores.