NEW YORK — The nation’s largest retailer keeps working to make headway against the largest online seller.

Walmart drew more shoppers to its namesake stores in the United States and its online sales soared 29 percent in the fourth quarter, which covers the critical holiday shopping season. That’s an indication that its efforts to lower prices and improve Web services are helping it compete better against Amazon, which has built fierce loyalty with its Prime two-day shipping program.

Like other traditional retailers, Walmart has been trying to improve its online operations to challenge Amazon, which accounted for 33 percent of total U.S. online sales last year, according to the research firm Euromonitor. Walmart moved into second place last year ahead of eBay, accounting for 7.8 percent of online sales, up from 7.4 percent in 2015. But its online sales are still a fraction of the company’s total business.

The holiday shopping season was tough for many retailers, underscoring the changes they need to make. Macy’s reported another quarter of sluggish sales, even as it has been scrambling for new ways to bring shoppers in and beef up online services. And Target, one of Walmart’s main rivals, warned last month of weak sales for the holiday season. It reports final figures next week.

“We believe Walmart is continuing to generate critical and increasing traction online,” said Moody’s retail analyst Charlie O’Shea.

Walmart has retooled its online shopping programs and bought up some smaller companies with online strengths. And its aggressive effort to harness the power of its huge number of stores with its online business is starting to take form.

“We’re moving with speed to become more of a digital enterprise and better serve our customers,” CEO Doug McMillon said.

Last year, Walmart spent more than $3 billion for Jet.com in a deal aimed at helping it attract younger and more affluent customers. Since then, it purchased online footwear retailer ShoeBuy.com for $70 million and the outdoor and gear seller Moosejaw for $51 million. These sites are operating as stand-alone sites. Walmart last year also raised its stake in JD.com, China’s No. 2 e-commerce site.

Marc Lore, the founder of Jet.com who is now CEO of Walmart.com, said Tuesday the company is still looking for new startups to buy. Under Lore, the company has quadrupled the number of items available on its third-party online marketplace to more than 35 million.