WhatsApp says it is now used by more than two billion people worldwide, marking a new milestone for the Facebook-owned messaging app.
It is estimated that there are more than 7.5 billion people on the planet, which means WhatsApp is now used by more than a quarter of all people on Earth.
In a blog post announcing the milestone, WhatsApp said strong encryption was a "necessity" in modern life.
Some critics, such as children's charity NSPCC, say messaging encryption makes it harder for police to track down criminals sharing illegal images.
People holding phones showing WhatsApp logo