WASHINGTON — Americans stepped up their online shopping and bought more autos in April, suggesting that consumers may be spending more than indicated by a slump among major retailers.

In a reassuring signal, the Commerce Department said Friday that retail sales climbed a seasonally adjusted 1.3 percent last month after a drop in March led by declining car sales.

But autos recovered in April, with sales jumping 3.2 percent. Sales growth was uniformly strong, online and off: Online purchases advanced 2.1 percent. Clothiers, restaurants, sporting goods stores, grocers, gas stations and even the embattled department store sector posted higher sales.

Only building materials stores suffered a monthly decline, though their annual sales growth was solid.

Over the past 12 months, total retail sales have risen 3 percent.

April’s sales gains paint a healthier picture of retail spending than did a slew of troubling reports released last week by Macy’s, Nordstrom, Kohl’s and J.C. Penney. Their gloomy figures had raised fears that consumers were pulling back at a time of meager economic growth, and retail stocks fell sharply in response.

But Friday’s government sales data offered at least a tentative hint that consumers may not be retrenching so much as shifting their purchases toward online retailers such as Amazon.com and thereby sapping traffic from the large retailers that anchor America’s major malls.