Most used social media 2021 | Statista
Market leader Facebook was the first social network to surpass one billion registered accounts and currently sits at more than 2.89 billion monthly active users. The company currently also owns four of the biggest social media platforms, all with over one billion monthly active users each: Facebook (core platform), WhatsApp, Facebook Messenger, and Instagram.
https://www.statista.com/statistics/272014/global-social-networks-ranked-by-number-of-users/