Human rights obligations require legislation and standards to ensure access to the web. To understand how standards support human rights obligations, this article uses a framework that differentiates the legal or practical use of mandatory and voluntary standards. This article demonstrates how voluntary web accessibility standards emerged from legislation in the United Kingdom, which suggests standardization processes mediate a standard’s use in law. Data from policy analyses and semistructured interviews demonstrate the association among policy actors, social institutions, and the use of a standard in law. This article recommends evaluating the impact of standardization processes in realizing human rights obligations.