One billion people have used Facebook in a single day for the first time in the site's 11-year history.
Facebook founder Mark Zuckerberg hailed the figure as an "important milestone" for the site, which in little over a decade has become an integral part of the lives of people all over the world.
In a post on his Facebook page, Mr Zuckerberg wrote: "We just passed an important milestone. For the first time ever, one billion people used Facebook in a single day.
"On Monday, 1 in 7 people on Earth used Facebook to connect with their friends and family.
"When we talk about our financials, we use average numbers, but this is different. This was the first time we reached this milestone, and it's just the beginning of connecting the whole world."
He said Facebook had blazed a trail in connecting communities globally and he is "proud" of the company's success.
He wrote: "Our community stands for giving every person a voice, for promoting understanding and for including everyone in the opportunities of our modern world.
"A more open and connected world is a better world. It brings stronger relationships with those you love, a stronger economy with more opportunities, and a stronger society that reflects all of our values."