The number of teenagers who say they are chronically online has nearly doubled since 2015, according to a survey from Pew Research Center. YouTube is the most popular platform among U.S. teens, with 95% of the coveted demographic saying they use the site or its mobile app, the survey found. TikTok, which was launched in the U.S. in 2018 and thus didn’t exist the last time Pew performed a similar survey, is now used by about 67% of those between 13 and 17-years-old.

Almost half of U.S. teens reported that they are online “almost constantly,” a jump from the 24% who reported similar behavior to Pew in 2015. On social media specifically, 35% of U.S. teens reported that they were on at least one of the major platforms almost constantly.