In this blog post, I will show you how to find free legal full-text open-access journal articles. In order to find the free scholarly literature, I use the Unpaywall -a free open-source tool.
In addition, I will also discover how to use the Unpaywall browser extension to unlock journal articles for free. This online tool lets you find open-access versions of full-text academic articles.
The Unpaywall provides you a link to legal, free open-access versions of paywalled articles you are reading. This ground-breaking tool unlocks open-access versions of articles behind paywalls.
At present, this handy tool indexes more than 27 million articles from more than 50,000 journals and open-access repositories.
Data Sources: How Does the Unpaywall Work to Find the Free Full-Text Journal Articles
When a researcher searches the paywalled articles through the standard web browser, this browser extension automatically checks its database ( an open database of 27,801,627 free scholarly articles as of writing this post) for an open-access version.
Unpaywall assembles full-text, free, and author-posted manuscripts from over 50,000 online open-access journals and repositories including Gold Open Access journals, Hybrid journals, institutional repositories.
If it finds a free open-access full-text version paper, you should see a green unlocked padlock key on the right side of your current page.
Besides, you can also search particular repositories and journals by name or URL ( Uniform Resource Locator) in lieu of the entire sources list through the below form:
If you want to download the full sources list as a CSV file click here.
How to Find Free Legal Full-Text Academic Research Articles
In this section, we demonstrate how to use the Unpaywall chrome extension to read an academic article for free. Here, we will be using the Google Chrome browser for this post.
Follow the below steps to use the Unpaywall plugin for finding safe and legal open-access journal articles:
Step #1: Install the Unpaywall Browser Extension
All you need to do is install the Unpaywall add-on to your browser to get it working properly.
In order to include the Unpaywall free plug-in to chrome browser, navigate to the Unpaywall’s website.
Moreover, you can also use the Firefox web browser to integrate this plug-in as it supports this browser.
After opening the site, this web page will appear:
Now, click the hyperlink “GET THE EXTENSION” button in the middle of the homepage to integrate it into your browser.
You should see the below page as soon as you click on the button:
Once you click the “ADD TO CHROME-IT’S FREE” button, you will be redirected to the chrome web store:
To include the Unpaywall plug-in to your browser you just click on the “Add to Chrome” button in the upper right corner of the page. You should see the below pop-up message:
Once you complete the installation the tab automatically appears when you are on a publisher’s web page. You do not need to do anything to verify the status of a given paper.
Step #2: Finding Free Legal Open Access Journal Article
Once you add the Unpaywall browser extension for accessing free online academic journals, you should see the page:
In this step, we show you the demonstration by clicking the “TRY IT NOW” button from their website.
The following snapshot of the online free open-access article will appear:
If the scholarly article is open access, you will see the green open padlock to the right of the page. If it is not available through open access you would see a gray locked padlock.
You do not need an account or log in to use this online widget. Here, we can see above the green open padlock that means the article is available.
Clicking on the green open padlock will take you to the full text of the scholarly article:
During the search of the paywalled journal papers, this smart tool automatically checks for a copy in its index of free, legal full-text PDFs.
Below is an example of what it will look like during the search of scholarly literature.
Here, we select this paper to access in our network:
“Prediction of protein subcellular localization by incorporating multiobjective PSO-based feature subset selection into the general form of Chou’s PseAAC”
As the above research article is not available through open access in our network that is why a gray locked padlock appears.
This padlock indicates that the tool can not connect you to an open-access version of this article.
Below is the snapshot of a paper that is not available:
If you click on the gray locked padlock, you will see the below message:
You can also set the “Open Access Nerd Mode” in the Unpaywall using settings option.
The snapshot of the Settings is given below:
Now, select the “Settings” option for setting the OA Nerd Mode. Once you click you should see the below sub-window:
You can switch to “OA-Nerd Mode” and see if the articles are Gold, Green or Bronze Open- Access.
The color code of the unlock tab to display whether full-text is:
In our previous post on Best 10 Chrome Extensions for Academic Research, You Should Know About we briefly discussed how to get free access to academic journals using various browser extensions.
Related Tools For Accessing Free Legal Full-Text Scholarly Publications
The Open Access Button (free and open-source) lets you search free, legal scholarly literature delivered automatically requested from authors. Apart from all the work, the OA button helps you email a request to the author for a full-text scholarly article if it is not available online.
The CORE Discovery offers the same services and allows you to find free copies of research papers whenever you hit the paywall. This tool supports chrome browser only.
The EndNote Click (Formerly Kopernio) is a literature search tool that lets you find and download PDFs from legally authorized sources. The free EndNote Click browser add-on supports Firefox and Chrome both browsers.
We discuss how to find free legal open access full-text journal articles using the easy-to-install Unpaywall tool.
Hopefully, this post was useful to you! What other tools have you used for the same purpose?
We would love to hear and learn from you. Please feel free to comment below.