The chapter compares the Global Reporting Initiative (GRI) Standards offered by the GRI organization with the International Integrated Reporting (IR) Framework issued by the International Integrated Reporting Council. Each of these documents provides a foundation to help create high-quality non-financial disclosure. This chapter analyses their approach to reporting quality by examining the concepts of materiality, reporting principles and content elements. The results of the comparative analysis present the core differences between the GRI Standards and the IR Framework, as well as how they are aligned and complement each other. The chapter also reviews previous research to answer whether the assumptions of the GRI Standards (formerly Guidelines) and the IR Framework have been implemented in the reporting organizations’ practice and how they have influenced the quality of disclosure. Finally, the chapter highlights the role of the GRI Standards and IR Framework in terms of incoming changes in the global sustainability reporting landscape.