Aldi crowned cheapest supermarket of the year, Which? reveals
Aldi was Britain’s cheapest supermarket in 2025, according to Which? analysis, with the most expensive supermarket costing on average 35 per cent more than the cheapest - potentially adding up to hundreds of pounds over the course of a year.
The consumer champion tracks grocery prices every day across some of the UK’s biggest supermarkets – Aldi, Asda, Lidl, Morrisons, Ocado, Sainsbury’s, Tesco and Waitrose – to see how much shoppers pay for everyday items such as milk, bread and frozen peas.
At the start of each month Which? then reveals the cheapest supermarket of the previous month based on a price comparison of a selection of products matched across the eight supermarkets. The analysis includes special offers and loyalty prices where applicable, but excludes multibuys.
In December, Aldi was the cheapest supermarket for a list of 68 items, with the basket costing £123.60 on average across the month. This confirms that in 2025, Aldi was the cheapest supermarket in 10 out of 12 months, securing its position as the UK’s cheapest supermarket for the fifth year in a row. Aldi does not operate a loyalty pricing scheme, meaning all shoppers pay the same low prices.
Lidl was a close second, costing just 10p more in December (£123.70), for both Lidl Plus members and non-members. Lidl was the cheapest supermarket twice last year in July and October, and across the whole year the average monthly price difference between Aldi and Lidl was just 77p - showing that Lidl is also a great value option for customers on a budget.
The analysis showed that at Asda, the same 68 items cost £134.89 on average in December, while still cheaper than most other supermarkets it was still around £11 more than shopping at Aldi.
For the same items, Which?’s price comparison showed Tesco Clubcard members would have paid £135.84 on average in December, compared with £139.12 without a Clubcard.
Meanwhile, the analysis showed Sainsbury’s Nectar card holders would have paid £141.45, rising to £143.74 without a Nectar card.
At the other end of the scale, Which? found the same basket cost £170.46 at Waitrose in December – £46.86 more than Aldi. Over the course of the year, Waitrose was 35 per cent more on average than the cheapest supermarket and 38 per cent more in December.
Which? also compared the cost of a much larger weekly shop of 180 items among the six non-discounter supermarkets. Aldi and Lidl are excluded from this comparison because they stock a smaller product range.
In December, Asda was the cheapest non-discounter supermarket with Which?’s list of items costing £450.82, continuing a pattern seen throughout the year. Asda consistently beat Tesco, Sainsbury’s and Morrisons, even when loyalty prices such as Clubcard and Nectar were included.
Which? found Tesco Clubcard holders would have paid £462 on average in December for the same list of items - over £11 more. The analysis also showed Tesco shoppers without a Clubcard would have paid £493.53 - or just under £43 more than those who shopped at Asda.
Shoppers at Morrisons would have paid £466.04 with a loyalty discount or £467.46 without - according to Which?’s price analysis - around £15 or £17 more than at Asda.
At Sainsbury’s, Nectar holders would have paid £468.61, while non-members would have paid £501.89 - over £51 more than an Asda shopper.
Meanwhile, those who prefer to shop at Ocado would have paid £498.19 in December for Which?’s list of 180 items - over £47 more than at Asda.
Once again, Waitrose was the most expensive supermarket for the larger shop (£529.17) according to Which?’s analysis. In December, the same trolley cost £78 more than at the cheapest supermarket - a difference of 17 per cent.
Across the year, the analysis shows that choosing the cheapest supermarket rather than the most expensive could save shoppers hundreds of pounds. On average across 2025, the most expensive supermarket was 35 per cent more than the cheapest for a smaller list and 15 per cent more than the cheapest for a larger list. This means households could make substantial annual savings by switching supermarkets.
Reena Sewraz, Which? Retail Editor, said:
“Aldi’s consistent performance shows why it has been crowned the UK’s cheapest supermarket for the fifth year in a row. While Lidl continues to provide strong competition among the discounters and is still a great option for those looking to save on their shopping, Aldi was cheapest in most months and offered the lowest prices overall.
“Our analysis also shows that Asda remains a strong choice for shoppers looking for a bigger range of branded goods at lower prices. With food bills still a major concern for many households, it really does pay to shop around – choosing one supermarket over another could save shoppers hundreds of pounds over the course of a year.”
ENDS
Notes to editors:
Each month Which? compares how much supermarkets charge for a selection of groceries, this month it compared 68 items that were available across all eight supermarkets. The data is based on availability across supermarkets each month, taken from its longer list of just over 200 items. Which?’s bigger list of groceries excludes Aldi and Lidl and this month compared 180 items that were available across the remaining 6 supermarkets. This list is made up of some of the UK’s most popular groceries, based on industry data on sales value and availability. Which? includes special offers and loyalty discounts where they apply but not multibuys.
Because the main list of around 200 groceries remains unchanged from month to month, Which? never shares the full list of products with retailers as it wants to avoid any attempt to skew the results. Which? does not want supermarkets to compete with one another to lower prices only on the items they know they will be judged on. Instead, it wants retailers to work to make groceries affordable across the depth and breadth of their available lines.
The cheapest supermarket results for December:
Which? checks the prices of hundreds of grocery items at eight major supermarkets throughout the year, using an independent price comparison website. For each supermarket, Which? works out the average price of each item across the month, then adds those up to get each store’s average price.
The consumer champion’s shopping list comprises the country’s most popular and widely available groceries, based on extensive market analysis. It includes branded items such as Cathedral City cheddar and Hellmann's mayonnaise, as well as own-brand products such as potatoes and baked beans.
Own-brand items won’t be identical across supermarkets, but Which? has ensured everything compared is as similar as possible based on a number of factors, including quality and weight.
Loyalty pricing
Which? looked at loyalty pricing for Lidl, Tesco, Sainsbury's, Morrisons and Waitrose, but none of the items on its shopping list had a loyalty price at Waitrose this month.
Asda's Rewards scheme offers cashback on products with loyalty promotions. Which? hasn’t factored this into its main analysis because loyalty members don't receive a discount on the day and the cashback is only redeemable at Asda, within a limited period (up to nine months) and in increments of £1.
As there are restrictions on who can access loyalty prices, Which? will only award a cheapest supermarket endorsement to the retailer with the lowest prices that are available to all consumers.
Useful links:
Cheapest supermarket monthly analysis
How to spend less at the supermarket
About Which?
Which? is the UK’s consumer champion, empowering people to make confident choices and demand better. Through our research, investigations and product testing, we provide trusted insight and expert recommendations on the issues that matter most to consumers.
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