Addressing the global challenge of vaccine hesitancy, amplified during the COVID-19 pandemic due to misinformation propagated via social media, necessitates innovative health communication strategies. This investigation scrutinizes the efficacy of Short, Animated, Story-based (SAS) videos in fostering knowledge, behavioral intent, and engagement around COVID-19 vaccination.We conducted an online three-arm parallel randomized controlled trial (RCT) involving 792 adult participants (≥18 years, English-speaking) from the United States. The intervention group viewed a SAS video on COVID-19 vaccination, the attention placebo control group watched a SAS video on hope, and the control group received no intervention. Our primary objectives were to assess the influence of SAS videos on knowledge, behavioral intent, and engagement regarding COVID-19 vaccination.Participants in the intervention group displayed significantly higher mean knowledge scores (20.6, 95 % CI: 20.3–20.9) compared to both the attention placebo control (18.8, 95 % CI: 18.5–19.1, P