A growing body of scholarship is becoming openly accessible – in other words, available free, immediately, and online without a paywall. This guide provides tips to help you find open access versions of articles and other scholarship.
Open Access Button: https://openaccessbutton.org/
The Open Access button searches across “all of the aggregated repositories in the world, hybrid articles, open access journals, and those on authors’ personal pages.” Supported by SPARC (Scholarly Publishing and Academic Resources Coalition), the OA Button builds on the work of librarians, researchers, and developers to provide an easy and legal strategy for locating OA research.
- Search for articles directly at https://openaccessbutton.org/
- The Open Access Button browser extension, available free for Chrome and Firefox, helps you to find open access articles as part of your regular search. When you are viewing an article with a paywall, click the OA icon in your navigation bar to see if an open version is available.
Unpaywall is built on a database of over 20 million OA articles and papers. According to their site, the data is sourced 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.” Founded in 2017, the tool is supported by the non-profit Our Research.
- The Unpaywall browser extension, available free for Chrome and Firefox, helps locate OA articles when you hit a paywall by searching for alternatives based on DOIs (digital object identifiers).
LibKey Nomad: https://thirdiron.com/downloadnomad/
LibKey Nomad is a browser extension you can install to enable library links to appear on external websites. This allows you to more easily access content via library subscriptions or request items from interlibrary loan.
- LibKey Nomad includes Unpaywall data to deliver Open Access versions when subscribed options are not available.
- See our brief libguide about LibKey Nomad.
LibKey.io is a look-up for articles by DOI (Digital Object Identifier) or PMID (PubMed Identifier). It provides options to “Download PDF” or follow the “Article Link” available via the UWM Libraries subscriptions and open access peer-reviewed manuscripts via Unpaywall; and also to “View article in context” of the journal issue via BrowZine.
More on using browser extensions to find OA research:
Chawla, D. (2017). Need a paper? Get a plug-in. Nature, 551, 399-400.
Open repositories host articles and other research outputs, usually deposited by the authors. The version available in the repository is often a pre-print – the version submitted by the author(s) prior to peer review. Repositories may be hosted by academic institutions, or they may be disciplinary in nature. Examples include:
- UWM Digital Commons
- articles, student papers, electronic theses and dissertations, and open journals by UWM faculty, staff, and student authors
- PubMed Central
- biomedical and life sciences journal literature
- physics, mathematics, computer science, quantitative biology, quantitative finance, statistics, electrical engineering and systems science, and economics
- aggregates papers from institutional and subject repositories; calls itself “The world’s largest collection of open access research papers”
- Open Access Directory: Disciplinary repositories
- organized by subject, a frequently updated list of OA disciplinary repositories
Contact the author
In most cases, authors are able to share their own publications on a one-on-one basis. Contact the author and ask for a copy: The author’s name and institution are usually shown on the preview page of the article.