TikTok hit 1 billion monthly active users globally this summer, marking a 45% jump since July 2020. The United States, Europe, Brazil, and Southeast Asia are the biggest markets for the popular short-video app. The company previously said it had about 55 million global users by January 2018, but that number rose to 271 million by December 2018, 508 million and 689 million by July 2020, according to the company.