Jet, the new shopping site that launches on Tuesday, promises shoppers “the lowest prices on everything.” To hammer home the point, the online mall will compare its price with Amazon’s price on every one of its product pages.

As a way to prove its marketing promise, Jet tested its service with some customers who were given early access by showing its prices against those found on multiple competing websites.

About 90 percent of Jet’s product listings at launch will show Jet’s discounted price compared with Amazon’s lowest price for the same item.