How it works

Once a day, we ask every retailer we track what they are currently charging for every item we follow. What comes back is stored exactly as given, with the time it was observed, and it is never rewritten afterwards.

That last part is the whole discipline. A recorded price is a fact about a moment, so correcting it later to something more flattering, or quietly dropping a reading that spoils a trend, would make the history worthless. Readings only ever get added.

It is what an item has actually sold for over the period we have recorded it. Not a recommended retail price, not a figure a shop has crossed out beside a sale badge, and not an average of the two.

This is the number worth comparing a current price against, and it is the one a shop cannot show you about its own products. A retailer can tell you today’s price is reduced. Only a record kept over time can tell you whether it is genuinely low.

A verdict on whether something is well priced needs enough history to support it. Where we do not have that yet, we show the current prices across retailers and say nothing about whether they are good.

The same applies to matching. Two listings are only compared when we are confident they are the same physical item, in the same colour and size. Where confidence is low we show the prices and make no historical claim, because a comparison between two things that merely resemble each other is worse than no comparison at all.

Where a retailer states a shipping cost, we add it and compare totals. Where a retailer states nothing, we show that it is unknown.

We never count an unstated shipping cost as zero. It is the single easiest way to make one retailer look cheaper than another, and it would be wrong exactly when it matters most, which is at the point somebody decides where to buy.

Prices, availability and history are kept strictly per country and never converted between them. A euro price converted into dollars is not what anybody pays: it ignores local tax, local shipping, local duty and the fact that the item may not be sold there at all.

So each country has its own record, built from its own retailers, in its own currency. A country is only opened once its history is worth reading.

Ranking is never sold. No retailer can pay to appear first, to be called cheapest, or to have a price described as good. We are paid affiliate commission when someone follows a link and buys, which is set out in full in the affiliate disclosure, and retailers we earn nothing from are shown alongside the ones we do.

If those two things ever came into conflict, the price record wins. It is the only reason to use this site rather than a shop’s own.