A man stands by a Yelp ground-delivery robot in San Francisco, the US on March 29, 2017. Photo: AFP

Americans are dining out in record numbers as pandemic restrictions lift, with restaurants struggling to keep up with demand amid a labor shortage, data released by review site Yelp showed Tuesday.

Yelp data showed more than 3.7 million diners seated using its app in May 2021, the highest number ever, surpassing pre-pandemic highs, according to Yelp restaurant marketplace manager Devon Wright.

The number of diners was 48 percent higher than in May 2019, according to the data.

The surge comes with a growing number of Americans having been vaccinated, and local governments gradually lifting mask mandates and limits on indoor dining.

"As diners head back into restaurants, new restaurant and food businesses are opening at near pre-pandemic levels," Wright said in a blog post.

"Nearly 6,600 new restaurant and food businesses opened in May 2021, a 42 percent increase from May 2020 and down by only 21 percent from May 2019."

Yelp also counted 16,500 reopenings in April 2021, with that number dipping to 5,000 in May.

The jump in restaurant dining has been especially pronounced in some cities seeing more tourism such as Honolulu (up 853 percent) and Las Vegas (up 589 percent), Yelp said.

Wright said restaurants are increasingly turning to technology to help manage the spike in light of difficulties in finding workers. This includes more use of digital menus, contactless payments, smartphone waitlists, reservations, and table management.

Pandemic restrictions have been gradually lifted in the US with just over 52 percent of the US population, or 174 million people, have already received at least one dose, according to health officials.