Black Friday shoppers wait to purchase goods at a Best Buy store on November 29, 2019 in Emeryville, United States. Black Friday is traditionally the biggest shopping event of the year, and marks the beginning of the holiday shopping season.

Black Friday brick-and-mortar retail sales fell by 6.2% compared to last year as consumers eschewed in-person shopping for online purchasing, according to preliminary data from ShopperTrak.

The pullback corresponds with a jump in Black Friday spending online, which hit $7.4 billion, the largest online Black Friday total ever, according to Adobe Analytics.

"There is no longer one way to shop on Thanksgiving Day and Black Friday," said Brian Field, senior director of global retail consulting for ShopperTrak. "Black Friday continues to remain the busiest shopping day of the year by a long shot."

The drop in Black Friday physical shopping mirrors a year-long share pullback in departments stores including Macy's, Kohl's and Foot Locker, all of which are down more than 25% this year. Meanwhile, Amazon, the dominant U.S. e-commerce retailer, has gained about 20% this year.

Brick-and-mortar sales on Thanksgiving Day rose 2.3% from a year ago, resulting in a combined 3% decline for the two-day period, according to the ShopperTrak data.

Eight of the 10 predicted busiest shopping days of the year are still to come as the December holidays arrive, according to ShopperTrak. Dec. 2, also known as Cyber Monday, is on track to break records as the biggest online sales day ever, at $9.4 billion, based on Adobe estimates.

Watch: Next retail revolution treating clients with dignity: Ethan Allen CEO