The social network said the new Instant Video feature would allow users to bring their text conversations to life in an "authentic way".
"It's perfect for sharing quick moments with friends who aren't right by your side or making your conversations richer by seeing each other face-to-face when you are messaging," said Facebook in a blog post.
"Sometimes you want to ask a friend’s opinion on a pair of shoes you want to buy, weigh in on what ice cream flavor they should bring home, or just want to see your BFF’s reaction to your witty message when you’re in a place where you can’t actually talk live."
The news comes just two weeks after Google launched its own video-calling app called Duo , in a direct challenge to Skype and Apple's FaceTime.
It works using your mobile number, so once you've downloaded the app and logged in using a Google account, you can immediately video call anyone on your contacts list who also has the app.
However, if you want to try out Instant Video in Facebook Messenger, here's what you need to do:
- First make sure that both you and your friend have the latest version of Messenger for either iOS or Android.
- Open up a Messenger conversation and tap on the video icon in the top right corner to start sharing real-time video.
- Audio is off by default, but sound can easily be turned on if you choose.
- Your video will float over the active text conversation, so that you can continue typing while viewing the video.
- Your friend can watch your video stream and share a video back if they decide.