Find free full text with browser extensions
- Get the Open Access ButtonThis open source project links you to free, legal, full text articles. You can search from their website or through their API, but their browser extension is the most convenient. When you're on the page of a paywalled article, click the extension and it will look for an open access version of the article. And if it can't find one, it makes it easy to request a copy from the author.
- Get UnpaywallThe browser extension Unpaywall, for Firefox and Chrome, adds a green tab beside research articles that you can read for free.
Free full text in Google and Google Scholar
Google and Google Scholar both include lots of material and use algorithms that are constantly being adjusted to highlight the "most relevant" results. Expect good recall, low precision, and little quality control.
When you search in Google Scholar, you'll see links labeled [PDF] to the right of search results. This connects you to full text from many resources: PubMed Central, ResearchGate, Academica.edu, or institutional repositories.
Do the same search in Google Scholar and Google, and you'll get different results. You can limit your Google results to PDFs by adding filetype:pdf to your search string; this can help you track down full text of articles, reports, and white papers.
Free full text in PubMed and PubMed Central
PubMed and PubMed Central are both free databases that you can search with high precision. To check which database you're using, look in the top left corner. Even though they look similar, there's an important difference! PubMed is a database of citations; PubMed Central is a database of articles.
It's almost always better to look for articles about your topic in PubMed, which is much bigger and updated more quickly. We recommend searching PubMed Central in one particular situation: if you need to search for keywords in the full text of articles.
PubMed has a free full text filter on the results page. Look on the left, under text availability, and click on free full text. The results set for your search will get smaller, but all the remaining articles are easily available in free full text. Just click on the article title to get to the article page, then look for the full text link on the right.That full text link will bring you to the article's full text, maybe in PubMed Central or maybe somewhere else.
Other resources for free full text
- HINARIAre you affiliated with an educational or health care institution in a low-income country? Talk to your organization about registering for HINARI to get free access to literature from many scholarly publishers.
- Open Access Dissertations and ThesesUse OATD to search almost four million theses and dissertations -- all open access. If you've been using Proquest Dissertations and Theses as a Yale affiliate, try this out.
- Open Science Framework Preprints"Preprints" are typically complete and public versions of articles before they have gone through peer review. Biomedical funders including the NIH and the Wellcome Trust have encouraged researchers to cite preprints as interim research products.
- Sci-Hub: an ethical conundrumYou've probably heard about Sci-Hub, an online collection of article PDFs. Before you decide to use Sci-Hub, you should read about the ethical conflicts of their approach; you can start with the coverage in Science, linked above. Librarians don't endorse copyright infringement -- that's why we have recommended all these other pathways to free full text.
You found it, but should you use it? Critical appraisal
- Evidence-Based Medicine WorksheetsUse these handy worksheets from Dana Biomedical Library at Dartmouth to appraise randomized control trials, systematic reviews and meta-analyses, practice guidelines, studies of diagnostic tests, prognosis studies, etiology studies, and qualitative studies. Don't outsource your critical thinking to journal editors and peer reviewers!