Facebook has unveiled a new version of its Messenger app which allows users without an account on the social network to join.
The update potentially allows Facebook to challenge platforms like Apple's iMessage and BlackBerry-maker RIM's BBM, which allow free messaging between devices over data connections.
The popular mobile messaging service WhatsApp is another potential competitor. It had been reported earlier this week that WhatsApp might be bought by Mark Zuckerberg's company, but that was denied.
WhatsApp currently has around 250 million users, and is available on both Android and iOS devices.
Facebook's new service also represents an obvious challenge to text messaging - which this week celebrated its twentieth birthday.
Facebook for Android will be the first version of the app to get the new service, the social network said.
A spokesperson said: "The feature will be available first on Android in Australia, India, Indonesia, South Africa and Venezuela and roll out globally in the coming weeks."