Health-related Web sites have become a primary resource to search for information on diseases, diagnoses or treatment options. Various Web sites offer a great variety of such information. However, lay people might have difficulties to assess whether a certain article or Web site fits their individual level of understandability. Hence, they might get overwhelmed with the delivered complexity of medical information. In this paper, we present a Web browser plugin, Expertizer that supports users in order to easily assess the expert level of textual medical Web content. The plugin communicates with a Web service, which leverages pre-computed classification models based on a Support Vector Machine.