This paper examines diversity in online news reporting and explanatory factors that shape news production. The analysis is based on online news from six countries (the United States, Germany, the United Kingdom, Switzerland, France, and Italy), comparing online-only news sites and legacy media. The analysis shows that most online media reported in a diverse way, comprising multiple topics and actors. Furthermore, event-driven news journalism explains the occurrence of high diversity in news reporting. Available resources and the intensiveness of online reporting (the extent as well as the editing style) also account for diversity. We draw from these findings to make a contribution to research on diversity in online news and to comparative communication studies. Qualitative comparative analysis is used to reflect on the direction and meaning of changes in journalistic practices in the current media environment.