How we collect and rank prices
Everything on this site is a number we looked up, ranked by one rule. This page says exactly how.
Where prices come from
For each product we query a shopping search index that aggregates online sellers' live listings, then read the product's seller list to get each seller's own page, item price and stated shipping. We keep the seller's direct product URL; we never link through a comparison intermediary. Sellers whose listing is hosted on a third party we can't link to are left out.
What "total" means
Total = item price + shipping when the seller states it in the listing. When shipping isn't stated we show a dash and rank on the item price; it's possible that seller is dearer once shipping is added. Tax is never included: it depends on where you are. The seller's checkout is always final.
Ranking
Lowest total first. That's the whole rule. The ranking code has no access to commission data — which sellers pay us, or how much — and a test in our build fails if anyone wires it in. A seller that pays us nothing is ranked exactly like one that does.
Condition
New-condition listings only, by default. Used, open-box, refurbished and "renewed" listings are kept out unless a reader or an assistant asks for them, and a page says so when nothing new was for sale. We also drop made-to-order and personalised variants, and we score down accessory listings that match a product's name (a "cooler pad" is not a cooler).
How often
Products someone has asked about recently are re-checked daily; the rest weekly. The "checked" time on every table is the real time of the last check. Price history is the lowest total we saw on each day.
Which products
Pages exist for products people asked an assistant about, and for the best-selling items in popular categories, which we discover automatically. A newly discovered product shows "price check scheduled" until its first full check. We don't accept product submissions or paid placement.
Head-to-head verdicts
A comparison page pairs two products from the same category whose lowest prices are within 60% of each other. The verdict is computed: which is cheaper today, which averaged lower over the history we hold, how many sellers carry each, and whether free shipping was shown. No opinion is involved; for which product suits you, read the buying guide.
Seller pages
A seller page lists every tracked product the store appeared on, its price next to the lowest we found, and the share of products where it was cheapest. Marketplace listings are attributed to the marketplace (a third-party seller on a big retailer's marketplace shows under the retailer's domain).
What we get wrong
Search indexes mislabel things. A sibling model can be matched to a product name, a bundle can appear as the bare item, and a price can be stale by the time you click. If you see one, email hello@gocottontail.com with the page link and we'll fix the record.
Money
Some seller links carry an affiliate code; the network pays us a commission on purchases made through them. It doesn't change the price you pay or the order of the table. The disclosure at the bottom of every page is the same sentence every time.
Disclosure: DealFinder by Cottontail earns affiliate commissions on some purchases made through links on this site and through its assistant tools. Commissions never affect ranking or the price you pay.