Google’s email service ‘Gmail‘ and Facebook-owned messaging app ‘WhatsApp‘ have both crossed the 1 billion monthly active user milestone, meaning that one-seventh of the world’s population now uses them both.

Google CEO Sundar Pichai shared the news with investors and media during Alphabet’s Q4 2015 earnings call on Monday, saying that Gmail hit the milestone in the past quarter.

This is the seventh Google service with a billion users, joining Search, Chrome, Android, Google Play, Maps and YouTube.

WhatsApp’s announcement came just moments after Google revealed the news. Facebook CEO Mark Zuckerburg took to his Facebook page to announce WhatsApp’s milestone. He wrote, “One billion people now use WhatsApp. Congrats to Jan (Koum), Brian (Acton) and everyone who helped reach this milestone!”

WhatsApp co-founder Jan Koum said in a post on Facebook that 42 billion messages, 1.6 billion photos and 250 million videos are shared every day on the platform, adding that there are now over one billion groups on the service.

WhatsApp is used in both the developed and developing countries, available across almost every platform and comes pre-installed on many feature phones used across the developing world, where smartphone penetration is still low.

Google’s Gmail, however, is a more resource-intensive application than WhatsApp despite having low-bandwidth versions of its webmail service. But the Gmail Android app crossed the billion installs mark in May 2014, becoming the first one to hit that milestone, with Facebook behind.

Unlike Gmail, the WhatsApp got there substantially quicker relative to its Play Store app. WhatsApp registered 1 billion installs on the Play Store in March last year, meaning it converted those installs into a billion MAUs in just 11 months. WhatsApp, of course, has also not been around nearly as long as Gmail, which makes it an even more impressive feat. Not to mention that in the US, most people have no clue about what WhatsApp is.