X launched the first major crowdsourced fact-checking experiment in 2021, originally called Birdwatch and now known as Community Notes. YouTube added its own in 2024, and Meta followed in a high-profile move that included severing professional fact-checking from its platforms.

Less than two months after Facebook added a new community notes feature that lets users add context to posts with missing or wrong information, TikTok is doing the same with something called Footnotes.