This article scrutinizes the role of transparency in the United Nations Framework Convention on Climate Change (UNFCCC). Specifically, it examines a widely heard claim that ‘transparency is the backbone of the Paris Agreement’, and the assumption that mandatory transparency (reporting and review) is essential to fill potential gaps in climate action left by voluntary, nationally determined climate targets. We subject this claim to critical scrutiny by tracing the political contestations around the desired role of transparency in the UNFCCC, with a focus on mitigation-related transparency. Our analysis shows that, despite developing countries expressing concerns during the pre-Paris negotiations, the Paris Agreement's enhanced transparency framework (ETF) is almost exclusively ‘enhanced’ (compared with earlier provisions) for developing countries, with some instances of regression for developed countries. Furthermore, the effects of such enhanced reporting are not straightforward and might de facto have an impact on countries’ autonomy to nationally determine their mitigation targets in diverse ways, even as all the detailed reporting does not facilitate comparability of effort. With implementation of the ETF due to start in 2024, our analysis provides a timely exploration of the extent to which transparency is really a backbone of the Paris Agreement, and for whom and with what implications for ambitious action from all under the international climate regime. It calls into question whether the transformative potential of transparency, much extolled within the UNFCCC process, will materialize for all countries in a similar manner or rather will have an impact on countries differentially.