E-commerce giant Amazon has overtaken Walmart as America's most-shopped retailer for apparel, new figures show. 

According to an annual US survey by Coresight Reseach, measured by number of shoppers, Amazon Fashion is the most-shopped clothing retailer in the US, up from second place in 2018. 

Apparel shopping rates show signs of peaking among Prime members, with three-quarters buying clothing on Amazon in the past year. Coresight recorded a much greater uplift from "have bought" to "expect to buy" among those without Prime membership than among Prime members.

As a group, the internet behemoth's private-label collections comprise the fourth-most-bought clothing or footwear 'brand' on Amazon, with one in six Amazon apparel shoppers surveyed saying they have bought Amazon private-label apparel in the past 12 months.

"Amazon has established its number one position by penetrating the heart of the mid-market," Coresight said. "Reflecting this, Walmart is now the top retailer that Amazon Fashion shoppers have switched some or all of their apparel spending from, followed closely by Target."

Meanwhile, Amazon Fashion shoppers are mostly satisfied with the site's online experience, citing the ease of browsing and searching as the top reason to buy apparel on the site. 13% of shoppers think that the site could be made easier to browse, however.

Yet Amazon apparel customers show only average rates of concern with sustainability. Overall, apparel shoppers try to buy from brands with a good environmental record but are less likely to want to pay for sustainable practices, Coresight said.

Amazon has made no secret of its desire to dominate in the apparel space and over the last few years has been building up its private-label clothing lines, as well as taking on a raft of brands such as Nike, Under Armour, Hanes, and Gildan Activewear.

The internet giant launched its first athleisure private brand, Aurique, in September of last year, adding to its portfolio of private brands which includes Truth & Fable, an occasionwear brand for women, Find, a street style inspired brand for men and women, Iris & Lilly, a contemporary lingerie label for women and Meraki, a premium basics brand offering menswear and womenswear.