broke the internet

Broke the internet describes online content—usually a photo, video, or announcement—that generates such massive traffic and social media attention that it metaphorically overwhelms the web's capacity.

The phrase is hyperbolic; nothing actually breaks.

It gained currency around 2014 when Kim Kardashian's magazine cover was promoted with the tagline: Her goal was to break the internet.

Now used for any viral sensation that dominates online conversation.