It’s always frustrating to hit a paywall when you stumble across an exciting article.
Until recently, for many of us the only legal way of getting hold of the publication was to purchase the paper in question. But that is no longer the case for millions of scientific publications thanks to Unpaywall – a free, open-source tool launched by ImpactStory – a nonprofit dedicated to making scholarly research more open, accessible, and reusable.
With Unpaywall you can find free versions of the full text research papers scattered around the internet. Unpaywall harvests legally-uploaded content from over 50,000 open data sources, including open repositories, open access and hybrid journals, as well as services like DOAJ, Crossref, and even Europe PMC.
In Europe PMC, free full text is already available for 4.6 million out of 33 million records. As for the rest, an open access copy may exist in a different repository, or reside on the publisher’s website. However, users have no way of knowing that the article they are interested in may be available elsewhere. And that happens more often than you think. According to a recent study, nearly half of all scientific articles requested by Unpaywall users are already available from one of the open sources.
We believe in the power of open science, but to unlock its true potential open content needs to be easily discovered. To help address this issue, Europe PMC has teamed up with Unpaywall to help users get open access to publications easily.
You can now see the iconic green Unpaywall logo on the full text link on the Europe PMC website whenever a free version of the paper can be found using the Unpaywall service.
Here is how we do it. If a paper is available in Europe PMC, the full text link will bring you right to it.
If, however, we do not have the free full text, we use the publication’s DOI to search for an open copy via the Unpaywall API. We then use the URL returned by the API as the full text link, which appears on the article’s abstract page, like in the following example:
Whenever possible, the link will bring you directly to the PDF version of the paper in question.
According to our estimations, this service will help users discover 2.7 million open access publications in addition to the 4.6 million free full text already available in Europe PMC.
Our goal is to build a system that helps you navigate the open content effortlessly. We hope that with this new tool many more of us in and out of academia will be able to read the research literature without any barriers.