Shoppers amassed at retailers across the country to shop deep discounts on Black Friday, but many stuck to the sofa and shopped deals from their smartphones.

Adobe Insights, which measures 80 percent of online transactions at 100 major U.S. retailers, said mobile transactions are "hitting record highs" this holiday season.

"The big story this holiday season is in mobile shopping," Mickey Mericle, the vice president of Adobe's Marketing and Customer Insights division, said.

"Shoppers looking for discounts are getting better at using smartphones to quickly close the deal, and we are seeing better mobile conversion this season at over 10 percent growth."

As of 10 a.m. ET on Black Friday, Adobe said 61.1 percent of shoppers' visits to retailers' websites stemmed from mobile devices, including smartphones and tablets. Those devices were driving 46.2 percent of total online revenue, as consumers had already spent more than $640 million by Friday morning. That's an increase of 18.4 percent compared with a year ago.