There are many third-party services that claim to add Facebook actual dislike button.
But since there is no official api for that, most of them ended up doing nothing.
So closest that we can get to the dislike button isby adding thumbs down image which looks like a dislike button.
There is a popular Facebook extension called "Dislike button for Facebook" that can add nearest possible dislike button onFacebook.
So how does it work?
After installing this extension user will notice a small dislike button start appearing in your Facebook Feed.
Click the thumb down button, and a dislike symbol will appear wherever, (status update, comment or chat) the user clicks on button.
So basically, this extension creates a small thumbs down icon and integrate it with your Facebook account.
So if you don’t like, agree to something you can show your exclusion by clicking on the dislike button.
And since it’s only an image, your friends can directly see it, without any need to download this extension.
However like the concept of real dislike button, you can down-vote or change the no. of likes in an update.
