David Karp (born July 6, 1986) is an American entrepreneur who started the website Tumblr in 2007. He sold the website to Yahoo! for US$1.1 billion in 2013. He was born in New York City. He started learning HTML when he was 11. When he was 15 he stopped going to high school. He was taught at home instead. In 2013, Forbes said that Karp's net worth is more than $200 million. is was Jewish.