Hi5 is a social networking site based in San Francisco, California. Founded in 2004, it was reported to be the 2nd largest social network after Myspace by 2007.In 2008, comScore reported that hi5 was the third most popular social networking site in monthly unique visitors behind Facebook and MySpace.

The social networking site, if(we), formerly known as Tagged, purchased hi5 in December 2011, for an undisclosed sumand operates it today.