Messenger once allowed users to chat across platforms, but now Meta is emphasizing the app’s ties to Facebook.

Facebook and Instagram parent company Meta Platforms Inc. says it will launch its crowd-sourced fact-checking program, called Community Notes, on March 18.

Meta began fact checks in December 2016, after President Donald Trump was elected to his first term, in response to criticism that "fake news" was spreading on its platforms. For years, the tech giant ...