Overall price comparison
On a like-for-like basket of groceries, Aldi and Lidl are consistently the cheapest UK supermarkets. They are typically within 1-3% of each other in overall basket price, with neither consistently winning across all categories.
The practical difference between them is usually more about store location, product range preference and availability in your area than price.
Where Aldi tends to win
Aldi's Everyday Essentials range provides very low prices on basics. Its speciality buys (the middle aisle's weekly themed ranges) are popular for non-food items.
For alcohol, Aldi's wines and spirits consistently receive strong reviews at low price points.
Where Lidl tends to win
Lidl's bakery range (Backerei) is highly regarded. Its fresh meat and fish counters in larger stores give it an edge for certain fresh products.
Lidl Plus app users can access targeted offers that can reduce costs further.
Which to choose
If both are accessible to you, the choice comes down to which has a store nearer to you, which carries the specific products you prefer, and personal shopping experience.
Many shoppers use both — and both represent a significant saving over the major supermarkets for most households.