Data sources

Unpaywall finds OA content in many ways, including using data from open indexes like Crossref and DOAJ where it exists. However, the majority of our OA content comes from independently monitoring over 50,000 unique online content hosting locations, including Gold OA journals, Hybrid journals, institutional repositories, and disciplinary repositories.

If you'd like to add your repository or to our list of sources, that's great! You can submit your repository for indexing via this form.