Is your grocery pack getting smaller? A free unit price checker for Lidl, Carrefour, Albert Heijn, Mercadona, ICA and more

Shrinkflation is when a product keeps its price but the pack quietly gets smaller: 500 g becomes 450 g, 1 l becomes 900 ml. The price tag looks the same, so most people never notice.

EU shops must show a unit price (per kg or per litre) next to the selling price under Directive 98/6/EC. In practice it is often small, hidden, or missing in online shops, and it never tells you that the pack was bigger last month.

What ShrinkWatch EU does

ShrinkWatch EU is a free, open-source extension for Chrome, Edge and Firefox. On a product page it:

• shows the price per kg, litre or piece in a small badge,
• cross-checks the shop's own unit price and tells you when they disagree,
• remembers pack sizes you have seen and warns you, for example "was 500 g, now 450 g, +11.1% per kg".

No account, no tracking, no network requests. Everything stays in your browser.

Shops checked on real product pages

Every shop below was opened in a normal desktop Chrome with the extension loaded, on a real product page, and the date and test product are logged:

• Germany: Lidl, Kaufland, Rewe, dm, Rossmann, Netto
• France: Lidl, Carrefour, Monoprix, Auchan
• Netherlands: Albert Heijn, Lidl
• Spain: Mercadona, Carrefour, Dia, Alcampo, Eroski, Lidl
• Italy: Conad, Lidl
• Poland: Lidl, Carrefour, Auchan
• Nordics: ICA, Willys, Mathem (SE), Nemlig (DK), K-Ruoka (FI)

The full list (71 shops, 66 verified) with dates and test products is on the compatibility page.

Per-shop guides: https://emirmrkaljevic.github.io/shrinkwatch-eu/shops/

Install in a minute

Instructions and the demo are on the project page.

Source and issues: https://github.com/emirmrkaljevic/shrinkwatch-eu

If your favourite shop is missing or shows a wrong figure, open an issue with the product link. That is how most fixes so far started.

This post was written with AI assistance and checked by me against the project's test logs.