Scholars across the globe are increasingly victims of repression due to their crucial involvement in critical knowledge production. Studies have pointed to the connection between this worrying trend and processes of global authoritarian regression, illustrating how the curtailment of academic freedom is often a harbinger of broader human rights violations. Less work, however, has gone into systematising, categorising and comparing the ways spaces for critical inquiry are curtailed. Concise catalogues that map out the defining features of academic freedom in an exhaustive way and that could thus provide the basis for systematic comparative investigation are conspicuously absent from the literature. This article intends to fill this gap by outlining the conceptual architecture of a comprehensive Academic Freedom Index (AFI). Spelling out a methodological path towards reliable parameters for assessing the regulation and restriction of research autonomy over time and on a cross-country level, it hopes to stir methodological debate and introduce a powerful instrument for advocacy.