The Budapest Open Access Initiative (2002) initially advocated for a new generation of Open Access (OA) journals that would find alternative sources of funding rather than subscription fees to ensure readers’ free and unrestricted access to scientific literature. However, author fees or article processing charges (APCs) have become one of the most widely adopted sources of funding by the OA journals that now dominate the publishing landscape, ultimately contributing to heightening inequalities among researchers. Diamond OA, a community-based non-commercial OA model in which scientific publications are free for both authors and readers, is generally considered a journal-based alternative to APCs. Despite concerns about their quality, sustainability, and overall lower scale and output compared to APC-based and closed journals, diamond journals are generally considered essential for local and underprivileged research communities. However, their lack of indexing in major bibliographic databases such as Web of Science and Scopus remains a challenge in assessing their uptake, contributing to the negative perceptions associated with them. OpenAlex, a new fully open index of scholarly communications based on an aggregation of data from various sources, could potentially be leveraged for the assessment of various aspects of diamond OA journals and papers, such as their relative impact and their distribution across languages, disciplines, regions, income groups, and collaboration patterns at a scale never studied before. This presentation aims to provide a global picture of the current state of adoption and impact of diamond OA based on their coverage in various data sources.