Courts around the world are increasingly acting as decision-makers in politically charged cases, such as climate change lawsuits. At the same time, however, their legitimacy is claimed to be eroding. No longer able to rely on their formal authority, courts must more frequently convince their respective audiences through the argumentative contents of their judgments. In this article, we develop a socio-legal method – comparative judicial discourse analysis (CJDA) – that enables the evaluation of the discursive quality and judicial legitimacy of such judgments from multiple jurisdictions. We test the method in action by applying it to a limited sample of court cases across five jurisdictions on the societally controversial and long-standing subject of copyright liability for online peer-to-peer platforms. Based on this experiment, we argue that CJDA permits drawing critical conclusions on the discursive, value-laden qualities of judgments to complement doctrinal legal reasoning. Our analysis teases out differences, and indeed possible deficiencies in courts’ argumentation, likely significant for the courts’ ‘throughput legitimacy’. Although the differences in discursive patterns are also affected by diverse legal cultures, case set-up, and institutional factors limiting a court’s deliberative freedom, we argue that the method contributes to the critical study of judicial argumentation, comparative analysis, and ultimately to research pertaining to the legitimacy of courts.