Facebook's laughing-face reaction is called Haha. It is one of the emotional reactions that appear when users press or hold the Like button on a post, comment, photo, or video.
Facebook introduced Reactions worldwide on February 24, 2016, expanding interaction beyond a simple Like. The original set included Love, Haha, Wow, Sad, and Angry. These choices gave users a way to respond emotionally without writing a comment, especially when a Like did not fully express their reaction.
Haha is often confused with informal terms such as “LOL,” but LOL is not the official name of Facebook's laughing reaction. Wow and Love are also official reactions, but their icons express surprise and affection rather than laughter. Facebook later added the Care reaction in 2020 during the COVID-19 pandemic, while the original Haha reaction remained part of the set.