Rolf Jacob Sartorius (born October 2, 2002) is an American social media personality and singer. He rose to fame via social media after posting lip-syncing videos on short-form video application Musical.ly. In 2016, he began releasing music with his debut single "Sweatshirt", which, along with his second single "Hit or Miss", charted on the Hot 100 in the United States and in Canada.