DealCheck is a free online price comparison tool that works instantly in any supermarket, grocery store, or convenience shop. Auto unit-price calculation โ no app download required, runs directly in your browser. Supports Thai and English.
Why compare unit prices?
Shelf prices don't tell the whole story. A larger bottle might look expensive, but when broken down to price per ml or g, it could be cheaper than the smaller one. A "Buy 1 Get 1" promo might look like a steal, but compared to a 40% off competing brand, it's not always the better deal.
Comparing unit prices helps you make the right decision every time โ saving money on every grocery trip. Over a year, those small differences can add up to hundreds of dollars in savings without changing how you shop.
How to read supermarket promos
Supermarket promos come in many forms. Understanding the real cost matters:
Buy 1 Get 1 (BOGO) โ equals 50% off per item (pay for 1, get 2)
Buy 2 Get 1 โ equals ~33% off (pay for 2, get 3)
% off โ straight discount from original price (40% off = pay only 60%)
Multi-pack โ check total volume ร price, e.g., 6-pack ร 325ml = 1,950ml total
Custom โ buy 3 get 2, buy 4 get 1, any combo โ DealCheck handles it
Pick the promo type in DealCheck and the app calculates the real per-unit cost instantly.
Real-world examples
Example 1 โ Bottled water: A 600ml bottle at $1 with 20% off vs a 1.5L bottle at $2. Drop both into DealCheck โ the large bottle is roughly 33% cheaper per ml.
Example 2 โ Shampoo: Brand A at 350ml for $5 with Buy 1 Get 1, vs Brand B at 480ml for $7. DealCheck shows A at $0.007/ml vs B at $0.015/ml โ A is more than twice as cheap.
Privacy-first, free forever
DealCheck was built for everyday shoppers โ no accounts, no login, no personal data tracking. All your comparison history stays in your browser's local storage, nothing is sent to any server.
The site shows small banner ads from Google AdSense to support development โ no full-screen popups, no intrusive overlays, and your data is never shared. Read more at our Privacy Policy.
Install as a mobile app: tap ๐ฒ in the header โ "Add to Home Screen" โ use it anywhere, even offline.
