How we check

Where the prices come from

We read prices from 14 retailers. For each one we record the price, the date we read it, and whether the product was in stock.

How often, and what happens when a price gets old

Most retailers are re-read every day. Some are slower, and a few can only be read weekly.

Every price on this site carries the date we last confirmed it. If a price is more than ten days old we fade it, label it, and leave it out of any “cheapest” claim. We would rather show you fewer confident answers than more confident-looking ones. Right now 96% of the prices we hold were confirmed within ten days.

We do not claim prices are live. A retailer can change a price a minute after we read it, and the price you see at checkout may differ once shipping, duties and any promotion are applied.

What we leave out on purpose

Some product formats cannot be compared honestly, so we exclude them from our published spread figures: sheet masks, pads, patches, stickers and jellies.

The reason is simple and it comes from getting it wrong. A single sheet mask priced at $4.00 was once compared against what was almost certainly a ten-pack at $27.92, and the result read as an 85.7% price gap. Nothing about that number was true. Until we can reliably tell a single unit from a multipack at the moment we read the page, those formats stay out.

We apply the same rule to bundles, gift sets, mini and travel sizes, and special editions. If two listings are not the same thing, we do not put a percentage between them.

What we do when a price looks wrong

A price far below everything else is usually a real sale. Sometimes it is our mistake.

So when a product is carried by three or more retailers, we set aside any price below half or above 1.8 times the middle price — unless a second, independent retailer is listing it within 25% of the same figure. A deep discount two shops agree on is a real event and we keep it. A lone outlier gets held back and looked at.

We added this after a cleanser was listed at $1.98 against a middle price of $11.50 and nearly became the headline finding in a report we send to brands.

This check needs three retailers to work. On products carried by only two, we cannot do it, and we say so rather than pretending otherwise.

What “cheapest” means here

The cheapest price we show is the lowest confirmed price among the retailers we read, on the date shown. It is not a promise that nothing cheaper exists anywhere. We only see the retailers listed above.

Shipping, duties and taxes change the real answer. Where a retailer publishes its shipping threshold or its duty treatment, we say so. Where it does not, we leave it blank rather than guessing.

How we make money, and what it does not buy

Some links on this site earn us a commission. That is disclosed on the pages where it applies.

No retailer or brand can pay to rank higher, to be listed as cheapest, to have a finding softened, or to be left out. The ordering is the price, and the price is the price. If a retailer asks to be removed from a comparison, the answer is the same for everyone: no.

What we do not claim

We do not say a seller is unauthorized. We do not hold any brand’s list of approved sellers unless that brand gives it to us, so that judgment is not ours to make.

We do not say a product is counterfeit. Our retailer tiers describe how a retailer sources and discloses, and nothing more.

We do not say a price breaks a brand’s minimum advertised price unless that brand has given us their floor in writing.

We do not claim to see everything. We see the retailers listed above, and on marketplace channels we see what that channel’s own search returns to a visitor in the United States. Some pages cannot be read on a given day, and when that happens we record it as unread rather than as nothing found.

When we get it wrong

We publish corrections rather than quietly editing them away. An index that shows its misses is easier to trust than one that has apparently never made any — and it is the only defence that still works the second time.

If you think a price or a claim on this site is wrong, tell us and we will check it and say what we found.

Related: how we rank · our trust contract