SEATTLE — For many people, buying clothing online is not worth the hassle of getting a pair of pants or a shirt that does not fit. Many retailers have sought to eliminate that risk by offering free returns on clothing, but now Amazon is going even further.

On Tuesday morning, the company revealed a new program called Prime Wardrobe that allows people to order clothing — from three to 15 items at a time — without actually buying it. Amazon will charge them only for the items they keep. Customers can return the items they don’t want in a resealable box with the preprinted shipping label that the order came in.

The service will be an option only for members of Amazon Prime, the company’s membership service, which, for $99 a year, gives customers fast shipping at no extra charge, a streaming video service and other benefits. The company did not say when Prime Wardrobe would be available.

It is hard to predict what impact this will have on the company’s clothing sales, but it follows a pattern at Amazon of eliminating so-called friction points to online shopping that have made it surprisingly successful in the apparel category.

By the end of this year, analysts expect that Amazon will become the largest apparel retailer in the United States, at a time when many traditional brick-and-mortar retailers are closing stores or filing for bankruptcy.

And retailers received a new reason to worry about Amazon’s ambitions in recent days after the company announced it had agreed to acquire Whole Foods, the high-end grocery chain, for $13.4 billion.

Amazon isn’t the first online company to offer a try-before-you-buy program. The eyewear retailer Warby Parker has long let customers try on up to five pairs of glasses at home for as long as five days, with no obligation to buy any of them.

Another online clothing retailer, Stitch Fix, offers a similar home try-on service. To use it, customers must pay a nonrefundable $20 “styling fee” through which they receive personalized clothing recommendations. The fee can be applied as a credit toward any items the customer buys.

Prime Wardrobe will let customers try on more than a million items of clothing, accessories and shoes from brands including Calvin Klein, Levi’s, Adidas, Hugo Boss and Lacoste without buying them. Customers will then have seven days to return the items they don’t want.

Introducing Prime Wardrobe
Video by amazonfashion

Previously, Amazon has tried to make its customers more comfortable with shopping for clothing online by offering free shipping on returns of most apparel. This allowed customers to buy clothing and receive refunds for any items they returned.

Free shipping on returns can easily erode the profits of an online retailer if customers use the option often, but Amazon can ease the sting somewhat because it also collects fees from its Prime members.

With Prime Wardrobe, Amazon will actually discourage clothing returns in a subtle way. The retailer will cut 10 percent off the purchase price of an order for anyone who keeps three to four items, and 20 percent off for anyone who keeps five or more items.