In the process of evaluating online learning products for accessibility, researchers in the Center on Online Learning and Students with Disabilities concluded that most often consultation guides and assessment tools were useful in determining sensory accessibility but did not extend to critical aspects of learning within the Universal Design for Learning (UDL) framework. To help fill this void in assessment, researchers created the UDL Scan tool to examine online learning products alignment to the UDL framework. This article provides an overview of how accessibility has been historically measured and introduces the need to move beyond the traditional understanding of accessibility to a broader UDL-based lens. With this understanding, a UDL Scan tool was developed and validated to investigate the alignment of online learning content to UDL. This article will present the process of development, the validation, and discuss how the measurements provide critical benchmarks for educators and industry as they adopt new online learning systems.