Facebook has launched a stand-alone website for its Messenger service, live at Messenger.com. Now you can use Facebook on the web to connect privately with your close friends without all the other distractions of Facebook.
You can however still access Messenger from within the original Facebook website. Just in case you're wondering, Facebook assures that the web version will not go the same route as mobile, where Messenger has been permanently separated from the primary Facebook app
You can try out Messenger on the web now by visiting Messenger.com