Unpaywall for Firefox

Many people feel that valuable knowledge should be available freely to anyone it may interest, including quite a few researchers, which is why they often upload their papers and allow them to be downloaded for free. The problem is finding these documents, as users often come across the articles on websites where they are hidden behind paywalls.

Unpaywall for Firefox is a relatively simple extension that does exactly what its name suggests: it allows you to get around these paywalls by finding full-text articles uploaded for free by the authors themselves, all with a single mouse click. If you aren't a fan of Firefox, a Chrome version of the extension is also available.

While it may seem too good to be true, rest assured that everything this Firefox extension does is perfectly legal, and it’s just as convenient as it sounds. Unpaywall only provides you with papers that were uploaded and made freely available by the authors themselves, even though a subscription is required to access them from certain websites.

The add-on’s developers claim that full-text versions can be found for 65-85% of articles, but this, of course, depends on the topic and when they were published. During our tests, we found that older papers were almost always available freely, but you may have a hard time finding articles that were published recently.

Unpaywall is remarkably unobtrusive, as you will not even notice it until you open a research paper in your browser. If the extension finds a free version of the article, it displays a green tab on the right side of the window, which you can click to open the document.

If you enable color-coding, the button will appear as gold, green or blue depending on the article’s licensing model. The gold tab indicates that the article is available under an open license, the green tab is for articles available on preprint servers or institutional repositories, while the blue one lets you know that no licensing information is available.

There is nothing negative to be said about Unpaywall for Firefox, as it does pretty much exactly what it says on the tin, and it is an invaluable tool for users who need to find scholarly articles for their research.

You can use this add-on to find free versions of most papers commonly hidden behind paywalls, and because the documents it finds were made freely available by the authors themselves, it is safe and perfectly legal.