Tumblr is an American microblogging and social networking website founded by David Karp in 2007 and currently owned by Automattic. The service allows users to post multimedia and other content to a short-form blog. Users can follow other users' blogs. Bloggers can also make their blogs private. For bloggers many of the website's features are accessed from a "dashboard" interface.
As of August 12, 2019, Tumblr hosts over 475 million blogs.
As of January 2016, the website had over 500 million monthly visitors, which dropped to less than 400 million by August 2019.