For discovering legitimate open access publications, comprehensive directories are essential starting points. The Directory of Open Access Journals (DOAJ) is a unique and extensive index of diverse open access journals from around the world, committed to ensuring quality content is freely available online for everyone. Similarly, the Directory of Open Access Repositories (OpenDOAR) is a quality-assured global directory of academic open access repositories. Other major directories include the Directory of Open Access Books and the Directory of Open Access Dissertations.
General-purpose repositories allow researchers to share various outputs, from datasets to preprints. Key platforms include:
- Zenodo: A general-purpose open-access repository developed by CERN and backed by the European Commission. It is free, has no upper data limits, and supports all research outputs.
- Figshare: An open-access repository that allows researchers to store and share a wide range of research outputs including datasets, presentations, videos, and code. It offers free storage up to 20GB for individuals.
- Open Science Framework (OSF): A free, open-source repository and project management tool supporting collaborative research, data sharing, and reproducibility.
- Harvard Dataverse: An open-source repository application for research data, free for all researchers worldwide with generous storage limits.
The table below compares some major free generalist repositories:
| Repository | Primary Cost for Standard Use | Key Limits for Free Tier | Notable Features |
|---|---|---|---|
| Zenodo | Free | 50 GB per record | Backed by CERN, supports all output types, versioning |
| Open Science Framework (OSF) | Free | 50 GB for open projects | Integrated project management, preregistration, collaboration tools |
| Harvard Dataverse | Free | 2.5 GB per file, 1 TB total per researcher | Tiered access controls, integrated data analysis tools |
| Figshare | Freemium (Free tier available) | 20 GB of private storage | Wide file format support, strong journal integration |
| Dryad | Data Publishing Charge (DPC) applies | $120 DPC for up to 50 GB | Curated, requires link to publication, enforces CC0 license |
Subject-specific and preprint repositories cater to disciplinary norms. Preprint repositories like arXiv, bioRxiv, and SocArXiv allow rapid sharing of manuscripts before peer review. Field-specific repositories also exist, such as SSRN for social sciences, ICPSR for social science data, and RePEc for economics.
A wealth of open data is available for reuse and analysis from governmental and institutional sources. Notable sources include:
- Government & Global Data: Data.gov, U.S. Census Bureau, World Bank Open Data, and UNICEF.
- Health & Scientific Data: NIH repositories, World Health Organization (WHO), CDC, NASA Earth Data, and Dryad Digital Repository.
- Academic & Social Science Data: ICPSR, Pew Research Center, Google Dataset Search, and Google Scholar.
Tools exist to help you find the right repository. The Registry of Research Data Repositories (re3data) is a searchable listing of data repositories worldwide. FAIRsharing is a curated portal describing standards, databases, and data policies. Experts also recommend checking guidelines from your institution or funder and, when possible, using a domain-specific repository to enrich metadata and discoverability within your field.
References
- DOAJ: Directory of Open Access Journals. doaj.org.
- Literature Review Made Simple: Comparing 4 open access repositories. Enago Academy.
- Data Repositories. Harvard Medical School Data Management.
- Institutional Repositories: Platforms. Atla LibGuides.
- 43 Free Open Data Sources You Shouldn’t Ignore. Crawlbase Blog.
- FAIRsharing | re3data.org. re3data.org.
- Open Access Dataset and Data Repositories. McMaster University MIRA.
- Data repositories | Digital Education Resources. Vanderbilt Libraries Digital Lab.
- Find a FAIR repository. International Neuroinformatics Coordinating Facility (INCF).
- Freely Available and Open Access Resources. UCLA Library Guides.