Since Japan promulgated the world’s first national hydrogen strategy in 2017, 28 national (or regional, in the case of the EU) hydrogen strategies have been issued by major world economies. As carbon emissions vary with different types of hydrogen, and only green hydrogen produced from renewable energy can be zero-emissions fuel, this paper interrogates the commitment of the national hydrogen strategies to achieve decarbonization objectives, focusing on the question “how green are the national hydrogen strategies?” We create a typology of regulatory stringency for green hydrogen in national hydrogen strategies, analyzing the text of these strategies and their supporting policies, and evaluating their regulatory stringency toward decarbonization. Our typology includes four parameters, fossilfuel penalties, hydrogen certifications, innovation enablement, and the temporal dimension of coal phasing out. Following the typology, we categorize the national hydrogen strategies into three groups: zero regulatory stringency, scale first and clean later, and green hydrogen now. We find that most national strategies are of the type “scale first and clean later”, with one or more regulatory measures in place. This article identifies further challenges to enhancing regulatory stringency for green hydrogen at both national and international levels.