Lidl was the cheapest supermarket in April, according to the latest monthly analysis from Which?.
We compared the prices for a basket of 18 popular grocery items every day in April and found that, on average, shoppers would have paid £25.92 at Lidl - beating rival discounter Aldi by just 74p.
Meanwhile, the most expensive supermarket was £9.14 pricier than Lidl for an equivalent basket of groceries.
Here we reveal the month's cheapest and most expensive supermarkets.
Every day in April we checked the price of 18 popular groceries, including Hovis wholemeal bread, unsalted butter and semi-skimmed milk, at the UK's biggest supermarkets to see how they compare.
The table below shows how much our basket cost on average:
Lidl () came out cheapest overall with the basket costing an average of £25.92, beating discounter rival Aldi () by 74p. While we can't compare exactly the same items each month because products aren't always available, this is the fifth month in a row that Lidl has been the cheapest supermarket.
The same basket of groceries was £9.14 more expensive at premium supermarket Waitrose.
Groceries with some of the biggest price differences for the month included own-brand olive oil, which was £2.39 at Lidl compared to £4.25 at Waitrose - a difference of £1.86.
We also compared a trolley of 63 grocery items (the original 18 plus 45 more).
This included a greater selection of branded items, including Cathedral City cheddar and Twinings tea bags, that aren’t always available in the discounter supermarkets – so for our bigger trolley, we haven’t been able to include Aldi or Lidl.
Asda - which has been the cheapest traditional supermarket every month since January 2020 - was the cheapest for our bigger trolley of items at £132.81. It was £17.01 cheaper than Waitrose, where the bill would have been £149.82.
We check the prices of hundreds of grocery items at eight major supermarkets every day throughout the year, using an independent price comparison website.
We work out the average price for each item at each supermarket across the month, and add the averages up to get an average trolley price for each store. We include special offer prices but not multibuys, to keep it as fair as possible.
Our shopping list combines branded items such as Kenco coffee, Oxo stock cubes and Twinings English breakfast tea with own-label products, including onions and milk. Of course, own-brand items aren’t exactly the same at different supermarkets, but we’ve used experts to ensure that the products are as comparable as possible based on a range of factors, including weight and quality.
Tesco, the UK's largest supermarket, has launched the 'Value Hacks' marketing campaign to identify ways customers could save money using its Clubcard scheme.
The supermarket giant warns that its customers have a total of £17m of unclaimed Clubcard vouchers due to expire in May - the total amount of the vouchers could fill up nearly 200,000 family cars with fuel.
Clubcard vouchers are handed out in February, May, August and November and are valid for two years.
You can check the expiry date of any vouchers in your account using the Tesco website or app. By logging in, you'll be able to see any points that haven't been spent yet.