Abstract:The interest in corporate sustainability has increased rapidly in recent years and has encouraged organizations to adopt appropriate digital communication strategies, in which the corporate website plays a key role. Despite this growing attention in both the academic and business communities, models for the analysis and evaluation of online sustainability communication have not been developed to date. This paper aims to develop an operational model to identify and assess the requirements of sustainability communication in corporate websites. It has been developed from a literature review on corporate sustainability and digital communication and the analysis of the websites of the organizations included in the "Global CSR RepTrak 2015" by the Reputation Institute. The model identifies the core dimensions of online sustainability communication (orientation, structure, ergonomics, content-OSEC), sub-dimensions, such as stakeholder engagement and governance tools, communication principles, and measurable items (e.g., presence of the materiality matrix, interactive graphs). A pilot study on the websites of the energy and utilities companies included in the Dow Jones Sustainability World Index 2015 confirms the applicability of the OSEC framework. Thus, the model can provide managers and digital communication consultants with an operational tool that is useful for developing an industry ranking and assessing the best practices. The model can also help practitioners to identify corrective actions in the critical areas of digital sustainability communication and avoid greenwashing.