A new survey about the use of social media and mobile devices by U.S. teenagers contains a few surprises.

Among the findings of the study by the Pew Research Center, which surveyed American teenagers age 13 to 17:

• Facebook remains the most used social media site with 71% using the site, even as half of teens use Instagram and 4 out of 10 use Snapchat.

• 92% of teens report going online daily — including 24% who say they go online “almost constantly.”• African-American and Hispanic youth report more frequent Internet use than white teens. Among African-American teens, 34% report going online “almost constantly,” as do 32% of Hispanic teens, while 19% of white teens go online that often.

• Nearly three-quarters of teens have or have access to a smartphone and 30% have a basic phone, while just 12% of teens 13 to 17 say they have no cell phone of any type.

• More than half (56%) of teens go online several times a day, and 12% report once-a-day use. Just 6% of teens report going online weekly, and 2% go online less often.

• African-American teens are the most likely of any group of teens to have a smartphone, with 85% having access to one, compared with 71% of both white and Hispanic teens.

• Teens are diversifying their social network site use. A majority of teens — 71% — report using more than one social network site out of the seven platform options they were asked about. Among the 22% of teens who only use one site, 66% use Facebook, 13% use Google+, 13% use Instagram and 3% use Snapchat.

• Boys are more likely than girls to report that they visit Facebook most often (45% of boys vs. 36% of girls). Girls are more likely than boys to say they use Instagram (23% of girls vs. 17% of boys) and Tumblr (6% of girls compared with less than 1% of boys).