Unpaywall : find open access versions of paywalled articles !

With new Chrome and Firefox extension - Unpaywall - you will find open access (OA) versions of paywalled articles as you browse. Behind Unpaywall there is Impactstory  - a nonprofit working to supercharge science by making it more open, reusable, and web-native. Impactstory is supported by grants from the National Science Foundation and the Alfred P. Sloan Foundation


Try Unpaywall Chrome/Firefox extension that gives you a link to a free PDF when you view scholarly articles (GitHub)


Researchers from all over the world are currently uploading their own fulltext PDFs to preprint servers and institutional repositories, making them free for anyone to read.

Nevertheless there is often no easy way to find them. 

Unpaywall is going to nurture the transition to fully open access scholarly publishing, by closing the gap between readers and freely-available full-text.

Unpaywall and ...

... the OA Button (working since 2013) are similar...

What is the difference between them?

The OA Button works on articles without Digital Object Identifiers (DOIs), and it helps you email a request for full-text to the author if none is available. It'll also help you find open datasets.

Unpaywall (working since April 2017) is largely built because folks wanted a demo for the open oaDOI API. Moreover, Unpaywall doesn't work for articles missing DOIs.

The great thing is, both OA Button and Unpaywall) are open-source and free, so you can install both, or fork 'em and make your own better extension!


What is the difference between them?

Like Unpaywall, Sci-Hub finds fulltext PDFs for paywalled articles. The main difference is where those PDFs come from: Unpaywall finds PDFs legally uploaded by the authors themselves, while Sci-Hub uses PDFs that are obtained by other means, including automated web scraping of publisher sites.

Sci-Hub's method delivers more comprehensive results, but is not super legal. Unpaywall offers a more sustainable approach by working within copyright law and supporting the growing open access movement.

Practically, when you hit a paywalled research article, Unpaywall automatically looks for a copy in its index of over 10 million free, legal fulltext PDFs.

In case Unpaywall find one, click the GREEN tab to read the articleWith Unpaywall you have a possibility to Legal open papers, instantly! 

Unpaywall finds full text about 25% of the time, although it varies a lot based on the age and field of the article.

The reason it's not 100% is because unfortunately not all authors upload their fulltext PDFs online - although the number is growing every day.

Unpaywall  gathers information from thousands of different legal, open-access repositories with the help many awesome open data sources, especially the DOAJ, Crossref, DataCite, and BASE.

In turn, Unpaywall makes all this data open for reuse via the oaDOI API: a free, fast, and very scalable way to leverage Unpaywall infrastructure to build your own projects.

Moreover...Unpaywall can tell you whether an article is "Green" or "Gold" OA:

Click the green Unpaywall extension icon in your browser toolbar and choose "options." Once there, tick Color-code tab for Green and Gold OA

Thence, you'll enjoy a veritable rainbow of OA colorfully goodness as you browse different articles:

  • Gold tab for Gold OA a rticles available from the publisher under an open license. (example)
  • Green tab for articles self-archived on a preprint server or institutional repository. (example)
  • Blue tab for articles available on the current page, but lacking license information (often that's because you're browsing from behind the paywall). (example)

It is still early days for Unpaywall project and it's under very active development. 

When you find an error, drop an email and the Unpaywall team will get it fixed for you.



Source: Unpaywall prerelease


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