Tumblr banned adult content from its platform in 2018. The company announced the change on December 3, 2018, and began enforcing the new Community Guidelines on December 17. The policy prohibited images and videos depicting sex acts, real-life human genitals, or female-presenting nipples, although limited exceptions existed for art, activism, and other contexts.
The ban followed years of increasingly strict restrictions. After Yahoo acquired Tumblr in 2013, adult-tagged blogs were gradually removed from search results and public tag pages. In February 2018, Tumblr also enabled Safe Mode by default for users, filtering sensitive content unless users opted out.
A common mix-up is confusing the announcement date with the enforcement date: the policy was announced in December 2018, but the platform-wide ban took effect later that month. Tumblr's decision also came shortly after its iOS app was removed from Apple's App Store over child-exploitation material discovered on the service.