The popular messaging app is now a third of the size of Facebook.
WhatsApp has announced that it now has 400 million monthly users.
Jan Koum, CEO of the popular messaging app took to the company's blog to break the news. According to Koum, WhatsApp has added 100 million regular users in just the past four months.
"WhatsApp has just 50 employees, and most of us are engineers. We've arrived at this point without spending a dollar on targeted ads or big marketing campaigns," Koum said.
With Facebook now claiming 1.2 billion users, WhatsApp is one third the size of the social giant. Mobile messaging is the new social battlefield, and WhatsApp seems ready to provide plenty of challenges to its competitors in the market.