This article centres on the variety of indexes of decentralization. The first section reviews and compares a dataset consisting of 25 decentralization indexes according to a series of items, namely the definition of territorial autonomy, the kind of units of analysis, the number of cases, the nature of variables, the timescale, the measurement frequency, the scoring, the sources, the validity and reliability assessment and the transparency of the data production process. It concludes by stating that the Regional Authority Index and the Local Autonomy Index are the rankings which best comply with these quality standards. In the second section, these two indexes are introduced along with the Territorial Political Capacity framework. While the former can be considered as the current international standards in the field of decentralization indexes, the latter proposes alternative ways to understand decentralization through using mixed methods.