Resource Review


Matthew B. Hoy, AHIP


Kopernio. Kopernio, 86–90 Paul Street, London, EC2A 4NE, United Kingdom;; pricing: basic extension is free, premium version may be available in the future; requirements: Google Chrome, Mozilla Firefox, or Opera browser and a valid email address.


A major challenge medical librarians face is connecting their patrons to full-text journal articles. Tools like link-resolvers and full-text databases can provide access to thousands of journals, but for these tools to work, patrons must begin their searches via their libraries’ websites. If library patrons search the open web and find a journal article on a publisher website, they do not have clear path to full-text access. Kopernio is a browser plugin aimed at solving this problem. This review describes what Kopernio is and how to set it up and explores some of its advantages and disadvantages. A brief discussion of similar products is also included.


Kopernio is a browser extension that simplifies finding full-text portable document format (PDF) copies of journal articles. The main interface is an icon overlaid on pages containing journal article information. If the web page a patron is using contains a journal article digital object identifier (DOI), Kopernio will attempt to locate a link to a PDF copy of that article. It does this by querying a list of known sources for articles, including publisher websites, open access repositories, and Google Scholar. If it can access a copy of the PDF, it will notify the user by changing the icon in the lower left corner of the screen. For some databases, including PubMed, Kopernio also integrates download icons into results lists, giving a quick and clear indicator which articles in a particular set can be easily accessed.

All users are also given a “locker,” 1,000 megabyte (MB) of online storage space associated with an account that users can create. Any articles retrieved via Kopernio are automatically stored in this locker for future reference. Articles stored in the locker can also be tagged and cited using a built-in citation tool. Users can also select a preferred search tool to integrate with the Kopernio toolbar button. Google, Web of Science, and PubMed can all be searched directly from the Kopernio button on the browser toolbar. Other available settings include preferred citation manager and citation styles.

One important feature of Kopernio is that users are always presented with the most authoritative version available of an article. Official publisher PDFs are given precedence over repository copies, and all PDFs are sourced from legitimate sources.


Kopernio requires minimal configuration. Once users have down loaded the extension in their browsers of choice, they will be asked to provide an email address and choose their home institutions. If their institutions have registered proxy information with Kopernio, user requests will be routed through that proxy. Users can log in to their institutional proxy once, and Kopernio will encrypt and store credentials in the browser, which speeds up the article retrieval process. Users can also select a preferred search tool to integrate with the Kopernio toolbar button.


There are several other tools that serve a similar purpose as Kopernio:


Kopernio is an extremely useful tool for users who search for journal article PDFs. The most appealing functions are the clear visual indicators for downloads and the ability to proxy links for users even if they do not find journals via the library website. The locker, citation management, and tagging features are a nice bonus but will probably only be of interest to power users.

Librarians will want to be sure they provide information about their institutions’ proxies to Kopernio, so that their users can benefit from this tool. Additional information about Kopernio and instructions for librarians to provide their proxy information can be found at Kopernio for libraries.

Matthew B. Hoy, AHIP,, Associate Director, Mayo Clinic Libraries, Mayo Clinic, Rochester, MN

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Articles in this journal are licensed under a Creative Commons Attribution 4.0 International License.

This journal is published by the University Library System of the University of Pittsburgh as part of its D-Scribe Digital Publishing Program and is cosponsored by the University of Pittsburgh Press.

Journal of the Medical Library Association, VOLUME 107, NUMBER 4, October 2019