Facebook is finally adding a dislike button, but it's not where you think. The social media network is testing reactions and the dislike button in messenger. The new feature is similar to the expanded reactions that are available on the newsfeed. Despite the company previously saying the dislike button won't be available on the newsfeed, it is among the most requested features. To use the dislike button, you hover over a message and tap the emoji button to add a reaction.