Here are some of the monthly active user statistics for various social media platforms, according to the search results:
Facebook - 2.96 billion monthly active users (MAUs) [1]
YouTube - 2.56 billion MAUs[2]
WhatsApp - 2 billion MAUs[3]
Instagram - 2 billion MAUs[3][4]
WeChat - 1.26 billion MAUs[2]
TikTok - 1 billion MAUs[2]
Facebook Messenger - 988 million MAUs[2]
Snapchat - 557 million MAUs[2]
Pinterest - 444 million MAUs[2]
Twitter - 368 million MAUs[5]
It's worth noting that these numbers are subject to change and may vary depending on the source. Additionally, there are many other social media platforms with significant user bases that are not listed here. When choosing which social media platforms to use for your brand, it's important to consider the relevance to your target audience and the quality of engagement on each platform, rather than just the number of users.
Was initially surprised about WeChat not being higher just because my understanding was that it was the main social site in China with a lot of the ones popular outside of that country being banned, but I suppose practically nobody outside of China uses it and they are still a minority of the world, big as they are, so on second thought it makes sense. Seeing Pinterest above Twitter genuinely surprises me though, I don't think I've ever seen anyone talking about Pinterest, mentioning their Pinterest account, or linking to it, and tbh I don't actually even know what sort of site it is or what it even looks like.