The Sustainable Development Goal’s (SDG) blueprint to global sustainability exemplifies the global governance trend towards the displacement of law by indicators. Indicators purport to produce objective measurement and comparison, a desirable trait for international public authorities that struggle to bolster the legitimacy of environmental and sustainability norms. This paper adopts a pragmatic approach to indicators by taking seriously their limitations, weaknesses, and dangers, but also their potential contributions to international sustainability objectives. We explore a reframing of the relationship between law and indicators in complementary, not adversarial, terms. Several examples of this complementarity are explored, including the potential use of the SDGs for evaluating the instrumental effectiveness of legal regimes, as well as the ways that international sustainability law supplements the SGDs by providing legal ramifications for violations of state-specific obligations. Finally, we argue that law and legal normativity make invaluable contributions to international environmental and sustainability governance, contributions that metrics and other managerial and technocratic forms of governance cannot make.