The open access coverage of OpenAlex, Scopus and Web of Science

Diamond open access (OA) journals offer a publishing model that is free for both authors and readers, but their lack of indexing in major bibliographic databases presents challenges in assessing the uptake of these journals. Furthermore, OA characteristics such as publication language and country of publication have often been used to support the argument that OA journals are more diverse and aim to serve a local community, but there is a current lack of empirical evidence related to the geographical and linguistic characteristics of OA journals. Using OpenAlex and the Directory of Open Access Journals as a benchmark, this paper investigates the coverage of diamond and gold through authorship and journal coverage in the Web of Science and Scopus by field, country, and language. Results show their lower coverage in WoS and Scopus, and the local scope of diamond OA. The share of English-only journals is considerably higher among gold journals. 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. Understanding the current landscape of diamond OA indexing can aid the scholarly communications network with advancing policy and practices towards more inclusive OA models.