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University of Minnesota

Kathryn A. Martin Library

Scholarly Publishing

What you need to know about journal impacts, acceptance rates, peer-review status, UMD's institutional repository, and who is citing whom.



An open database of 23 million free scholarly articles

Unpaywall is a browser extension that works with Chrome and Firefox. Unpaywall points researchers to legal open access versions of articles. It is also integrated with several research databases available to the UNLV community including Scopus, Web of Science, and Dimensions (all available from the Library Databases list).

Once the browser extension is installed, researchers will see a color coded lock on any record where a Digital Object Identifier (DOI) is available.

  • Green means an OA article has been found
  • Grey means no legal OA copy could be found

Choosing OA Nerd Mode

You may choose to adjust the extension settings (right click on the extension at the top of your browser window). Doing so gives you additional information about the open access articles:

  • Green means an open access manuscript has been found
  • Gold/Yellow leads to open access articles available from a publisher
  • Bronze indicates freely available from the publisher, at least temporarily
  • Grey indicates "The Unpaywall extension couldn't find any legal open-access version of this article"

Instructions for installing and using UnPaywall

  1. Visit the Unpaywall page using the Chrome or Firefox Browser
  2. Choose Get the Extension
  3. Choose Add [to Chrome or Firefox]
  4. Choose install
  5. Follow the instructions on your computer to give permission to install the plug-in
  6. Conduct a search for research articles and check for the lock on any article page - is it any color other than gray? If so, click the lock to access the article you seek.

Open Access Button

Free, legal research articles delivered instantly or automatically requested from authors.

The open access button assists researchers in requesting copies of works that are not currently open access. If you discover an article with a paywall you may wish to request that the author make an open access copy available.  The button works by checking to see if there is an open access copy, and if not prompting you to complete a few short questions about the work and the need for the article, and then a request is sent to the author on your behalf. The hope is that authors will choose to make their work available via a legal, open access route.

Note: If you are affiliated with UNLV, you have many ways for obtaining works behind paywalls including accessing library paid subscriptions from off campus and interlibrary loan. Check the library website to learn more about these services.

Instructions for Installing and Using the Open Access Button

  1. Visit the Open Access Button webpage
  2.  Click the link to Get the Browser Extension
  3. Follow instructions on your computer to give permissions to install the extension.
  4. Continue with your research and use the button when you wish to ask the author to make a work open access.
    • You will be prompted to answer some questions about your request for the article and for author contact information as well.

Other Sources for Open Content

Open Educational Resources

There are many individual OER sources available. The widget below, developed by George Mason University, allows searching through many of them. The list of sources included in the Mason OER Metafinder are listed (and linked) below:

Using the Mason Open Metadata widget will open a new window in your browser. If you prefer to search directly from your desktop go to