Current warnings in Web browsers are difficult to understand for lay users. We address this problem through more concrete warning content by contextualizing the warning – for example, taking the user’s current intention into account in order to name concrete consequences. To explore the practical value of contextualization and potential obstacles, we conduct a behavioral study with 36 participants who we either confront with contextualized or with standard warning content while they solve Web browsing tasks. We also collect exploratory data in a posterior card-sorting exercise and interview. We deduce a higher understanding of the risks of proceeding from the exploratory data. Moreover, we identify conflicting effects from contextualization, including distrust in the content, and formulate recommendations for effective contextualized warning content.