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Open Access@HKUL: Open Access Tools

Open Access Tools

More and more published papers are now freely available through repositories and preprint servers, etc., but finding them isn’t always easy. There are several new tools and plugins are available to detect free OA versions.

Unpaywall searches the Unpaywall database which works by harvesting from Open Access sources to find OA content and then matching that content to the Crossref DOI.

Find open-access versions of paywalled research papers, instantly with this web browser extension for Chrome and Firefox. A green “unlock” sign means that a free version of the paper is available elsewhere. A grey “lock” icon means that a free version was not found.

The Unpaywall extension is already integrated into lots of tools and platforms such as Web of Science, Scopus and Zotero.



EndNote Click is the free web-browser plug-in to find the “Best Available Full-text PDF” of an article and works with one click. Users can click on a button to bring up the available PDF. You can set up EndNote Click with HKU as your institution so that it will check HKU Libraries subscription first before delivers an OA version.

For more information about EndNote Click, please refer to here.

Add the Google Scholar Button as an extension to your browser. You can then look up resources as you browse the web by highlighting the text you want to search for and clicking the button. It will automatically run a search in Google Scholar and returns the top results in a little popup window on the web page you are on.

The results include links to the full-text (Subscription or Open Access), you may wish to set up “The University of Hong Kong” in your Google Scholar settings to get our libraries subscriptions in the search result.

Open Access Button searches thousands of sources containing millions of articles to connect you to an article instantly if it is freely available.

You can download the Open Access Button Chrome browser extension to get you instant, legal access to articles.

The sources include all of the aggregated repositories in the world, hybrid articles, open access journals, and those on authors personal pages.

If this plug-in can't find the open article, it allows you to automatically email the author to request the article.

Data and Scholarly Communication Librarian

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Jesse Xiao
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