Same barcode, three prices: which Vietnamese supermarket is cheaper
Cá Buồm matches groceries from Co.opmart, WinMart and Kingfoodmart by barcode. On 15 Sep 2026, 7 out of 10 products sold by two or more chains differed by 5% or more, and the cheapest chain is not the one you would guess.
Published 15 September 2026
A one-litre carton of Devondale milk has exactly one barcode: 9300639603018. On 15 September that carton sold for 51,000₫ at WinMart, 67,900₫ at Co.opmart and 79,900₫ at Kingfoodmart. Same factory, same pack, a 57% difference. This is the story Cá Buồm was built to tell every day.
Matched by barcode, not by name
Every supermarket writes product names its own way: “1L carton” here, “1 litre” there, “full cream” added somewhere else. A machine cannot trust names. The only number that is identical everywhere is the EAN barcode printed on the pack. Cá Buồm reads the barcode from each chain’s product page and matches on it: same code, same product.
A case and a single unit carry different codes, but some shops list a ten-pack under the barcode of one pack. So any name that starts with “Thùng”, “Lốc” or “Combo” is kept apart and never merged with the single unit.
The numbers on 15 Sep 2026
Out of more than seven thousand items read from the three chains, 252 products are sold by two or more of them, eight by all three. For those products:
- the average gap between the cheapest and the dearest shop is 16%;
- 7 out of 10 differ by 5% or more;
- the most overlap is in drinks, pantry goods and dairy.
Cheapest chain by number of wins:
| Chain | Products also sold elsewhere | Cheapest among them |
|---|---|---|
| Co.opmart | 178 | 125 (70%) |
| WinMart | 104 | 46 (44%) |
| Kingfoodmart | 230 | 88 (38%) |
Co.opmart wins most often, but not on everything: fresh milk is cheaper at WinMart, laundry detergent at Kingfoodmart.
A few examples
- Coca-Cola 320ml can: 8,000₫ at Co.opmart, 12,000₫ at Kingfoodmart.
- Boncha honey kumquat tea 450ml: 8,000₫ against 13,000₫.
- CP cocktail sausages 250g: 37,200₫ against 56,000₫.
- Blue laundry liquid 3.6L: 159,000₫ at Kingfoodmart, 229,000₫ at Co.opmart.
- Devondale milk 1L: 51,000₫, 67,900₫, 79,900₫.
Prices are re-read every night, so by the time you read this the figures may have moved. The product page always shows the latest price and the date it was read.
How to use it
Open the home page, choose Groceries and switch on the 2+ shops filter: what remains is exactly the set of products you can compare, sorted by how much you save. Or type a name into the search box, accents optional: “sua tuoi”, “nuoc giat”, “coca”.
Cá Buồm sells nothing and takes no money from any shop for placement. Links go straight to the shop page; check the price there before you pay.
