Educational videos on social media are widely used in informal learning. However, empirical studies hardly look into sensemaking, a key aspect in the construction of meaning and knowledge, of educational videos on social media in informal learning, despite the growing interest and practice in educative sensemaking. This study addresses this research gap. We draw upon sensemaking theories and investigate how the physical properties of educational videos affect sensemaking. Our research shows how information control, anchor, and noise are associated with committed interpretation in the learning communities to understand the scientific inquiry at hand with data from YouTube educational videos. This study makes timely contributions to the literature on the educative sensemaking in informal learning on social media. It also offers insights into the better design of educational videos to facilitate sensemaking and informal learning.