ShrinkWatch EU is a free, open-source browser extension for grocery shopping in the EU. On product pages at 71 shops it shows the price per kg or litre, and it warns when a pack gets smaller for the same price. 66 shops are verified, and 5 are unverified because they block the test browser or need a login. Installs on Firefox from the Mozilla add-ons store, while Chrome, Edge and Brave need a manual install from a release zip. History stays on the device, with no account and no tracking. Source is MIT on GitHub.
I got tired of comparing grocery packs by eye. Shops in the EU print a unit price in store, but online it is often missing or easy to miss, and shrinkflation is hard to spot from the pack price alone. I built ShrinkWatch EU so the price per kg or litre is on the product page, and a warning appears when the pack gets smaller for the same price. It runs only in the browser. No account and no tracking.