Diamond open access

Diamond open access refers to academic texts (such as monographs, edited collections, and journal articles) published/distributed/preserved with no fees to either reader or author. Alternative labels include platinum open access, non-commercial open access, cooperative open access or, more recently, open access commons. While these terms were first coined in the 2000s and the 2010s, they have been retroactively applied to a variety of structures and forms of publishing, from subsidized university publishers to volunteer-run cooperatives that existed in prior decades.

In 2021, it is estimated that between 17,000 and 29,000 scientific journals rely on a diamond open access model. They make up 73% of the journals registered in the Directory of Open Access Journals and 44% of the articles, as their mean output is smaller than commercial journals. The diamond model has been especially successful in Latin America-based journals (95% of OA journals) following the emergence of large publicly supported platforms, such as SciELO and Redalyc. However, Diamond OA journals are under-represented in the major scholarly databases, such as Web of Science and Scopus. It is also noteworthy, that high-income countries "have the highest share of authorship in every domain and type of journal, except for diamond journals in the social sciences and humanities".

In 2022, new national and international policies, such as the UNESCO recommendation on open science, and the Action Plan for Diamond Open Access promoted by the cOAlition S aim to support the development of non-commercial or community-driven forms of open access publishing.