- Who
- What
- 2,375,000,000 people
- Where
- Not Applicable ()
- When
As of 29 April 2019, Facebook was the world's largest online social network, with 2.375 billion monthly active users (MAU) based on Q1 2019 results. Facebook reached the 2-billion monthly user milestone on 30 June 2017.
By comparison, Instagram has a reported 1 billion monthly active users (as of June 2018) and around 321 million for Twitter (as of February 2019).