This qualitative interview study explores the perceptions five USC Shoah Foundation Master Teachers who integrate Holocaust survivor and witness testimony via IWitness, a web resource from the USC Shoah Foundation, on students' development of empathy. Findings of this study suggest that the personalized nature of engaging with testimony in IWitness promotes student development of empathy and historical understanding. Specifically, teachers' perception suggests that testimony humanizes the content of the Holocaust and students develop emotional connections with the survivors. These connections suggest deeper understanding of the content and students' sense of empathy was evident in subsequent activities, both within the class and beyond.