Methodology

Price sources

Prices are collected from the public product-listing pages of the stores named on this site, at a gentle pace. We never estimate or guess a price.

Product matching

Two offers are linked to the same product first if the valid barcode (EAN/GTIN) matches; otherwise only if name, brand and size or unit count (for example 200 ml or 30 capsules) are very close. We never merge two products with different barcodes, and when unsure we do not merge. A product is published only if it is currently in stock at two or more stores.

Size and offers

Prices can vary with size, current promotion and delivery fees, which is why we match size or unit count before comparing. Check the details on the store page before buying.

Update schedule

The last-update date is shown on every page and in the open data. A store's price may change after our last update.

Validation

We drop invalid (zero or negative) prices and prices more than 30% below or 45% above the product's median. If only two stores remain and their prices differ by more than 50%, we do not publish the product because we cannot tell which is right.

Ranking & commissions

We may earn commissions through some links in the future; they never affect store ranking or displayed prices, and we will say so clearly.

Open data

All prices are available as JSON at /para/sa/api/products.json for use and citation with attribution.