This chapter investigates the ways in which the platform where news is encountered influences what audiences perceive to be news and how they make assessments about news-ness—a concept designed to allow audiences to decide the degree to which content is or is not news. An experimental design is used to compare how people respond to identical news content when it is posted on a news website versus by a news organization on Twitter. The results suggest that content seen on the Associated Press’s website is viewed as higher in news-ness across several topics compared to that content seen on its Twitter feed. However, the news cues people employ to make these judgments about news-ness are largely similar across both platforms. This chapter demonstrates that platforms and their attributes remain consequential when audiences decide what news is in a shifting media landscape.