The world’s largest retailer is taking on online retail giant Amazon.

Walmart Stores Inc has announced its opening ShippingPass, its shipping program to all shoppers in the U.S.  The program gives customers free, unlimited two-day shipping on items purchased on walmart.com and costs $49 a year.

The decision comes as Walmart looks to directly compete with Amazon’s Prime subscription service which costs $99 a year.

In order to generate interest, Walmart has launched a free 30-day trial of ShippingPass.

Walmart, in recent years, has introduced several programs, including online grocery pickup and delivery, boost sales.