The company's co-founder and chief Mark Zuckerberg revealed the ongoing tests during a question and answer session on Tuesday held at Facebook's headquarters in Menlo Park, California.
"People have asked about the 'dislike' button for many years, and probably hundreds of people have asked about this, and today is a special day because today is the day that I actually get to say we are working on it, and are very close to shipping a test of it," he said.
The "dislike" button has been a subject of much discussion over the years.
The CEO said the company has been working on the feature—which would allow users to express emotions other than "like"—for some time because "we don't want to turn Facebook into a forum where people are voting up or down on people's posts."
"That doesn't seem like the kind of community that we want to create: You don't want to go through the process of sharing some moment that was important to you in your day and have someone 'downvote' it," he said, using the lingo of popular online forum Reddit.
Instead, Zuckerberg said, the new feature will allow people to "express empathy" with their Facebook friends, explaining what many users of the social media platform already knew: "If you are sharing something that is sad...then it may not feel comfortable to 'like' that post."
