YouTube says more than 1 billion people around the world now watch videos on the site.
The announcement comes five months after Facebook said its number of users had reached the same number.
Following its launch in 2005, Google bought YouTube for 1.76 billion dollars (£1.2 billion) in 2006 when the video site had an estimated 50 million users worldwide.
Since late 2011, YouTube has refocused its site to prioritise watching along distinct channels of its creators. Such channels were seen as better allowing advertisers to focus on certain genres of content like beauty or music.
In 2012, it seeded 96 channels with around 100 million dollars (£66 million) in funding to help them accelerate that growth, often partnering big-name Hollywood producers and directors who had made it big in movies or TV but not on the internet, including CSI creator Anthony Zuiker.
But yesterday's event focused largely on those who had succeeded on YouTube before the channel-funding strategy was in place.
Robert Kyncl, vice president and global head of content partnerships, acknowledged that the strategy had not worked as well as hoped.
When asked if the investment had paid off, he said: "Every year, we reserve the right to get smarter."
He said more of such investment in the future would go to channels that had proved they can build an audience on their own.
"What we're looking for is the acceleration of those who are figuring out how to retail their content," he said.
Read More
MORE ABOUT