Aldi has been officially crowned the cheapest supermarket in the UK for an unprecedented fifth consecutive year, according to a major annual study. Research by the consumer champion Which? found that shoppers could save hundreds of pounds over a year by choosing the German discounter over its rivals.
The Price War: Discounts Dominate
The analysis, which tracked daily prices for everyday items like milk, bread, and frozen peas across eight major chains, revealed that Aldi was the cheapest in ten out of the twelve months of 2025. Its main rival, fellow discounter Lidl, provided fierce competition, taking the top spot in July and October. However, over the entire year, the average monthly price difference between the two was a mere 77 pence.
In a direct comparison for a basket of 68 items in December, Aldi's total averaged £123.60. Lidl was a razor-thin second at £123.70 for both members and non-members of its Lidl Plus scheme. This highlights that Aldi achieves its low prices without needing a loyalty card scheme.
How the Big Four Stack Up
Among the larger, traditional supermarkets, Asda emerged as the clear price leader, consistently beating Tesco, Morrisons, and Sainsbury's. This held true even when the rivals' loyalty card prices were factored in.
For the same December basket, Asda's cost was £134.89—still over £11 more than Aldi. Tesco Clubcard holders would have paid £135.84 on average, while Sainsbury's Nectar card holders faced a bill of £141.45. At the premium end, Waitrose was the most expensive, with the basket costing £170.46—a staggering £46.86 more than Aldi.
The Big Weekly Shop Comparison
Which? also conducted a separate comparison for a larger weekly shop of 180 items, excluding Aldi and Lidl due to their smaller ranges. Here, Asda was the cheapest throughout the year, with the December trolley costing £450.82.
Tesco Clubcard holders would have paid £462, Morrisons shoppers around £466, and Sainsbury's Nectar holders £468.61. Once again, Waitrose was the most expensive at £529.17, making it £78 more than shopping at Asda.
Industry Reaction and Consumer Advice
Reena Sewraz, Which? Retail Editor, stated: 'Aldi's consistent performance shows why it has been crowned the UK's cheapest supermarket for the fifth year in a row... 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.'
Aldi celebrated its victory by releasing a series of 'Brag Bags' with playful slogans like 'Aldi. No loyalty card needed'. Julie Ashfield, Aldi UK's Chief Commercial Officer, said the company was 'incredibly proud' of the achievement.
An Asda spokesperson highlighted their 'clear, consistent pricing, that's available to everyone' without a loyalty card. Waitrose defended its position by emphasising value beyond price, citing exceptional product quality, customer service, and leading ethical sourcing standards.
The news follows strong Christmas trading for both discounters. Aldi reported a 3% sales rise to £1.65bn in the four weeks to Christmas Eve, while Lidl saw a 10% surge, with turnover exceeding £1.1bn. The data underscores the ongoing shift in the UK grocery landscape, where discounters continue to gain market share by prioritising low prices for cost-conscious consumers.
