Below you can find a list of Open Access harvesters and PrePrint servers that can help you locate free full-text content.

Harvesters

base

Bielefeld University Library Open Access catalog.

unpaywall

Chrome extension for locating Open Access content.

core

Open Access aggregator.

doaj

Directory of open access journals and articles.

13-kopernio

Kopernio is a browser plugin that finds the best available PDF of an academic article while you browse. 

oaister

OAIster is a union catalog of millions of records that represent open access resources.  

Preprint servers

BioRxiv

Preprint repository for the biological sciences.

asap

Preprint server in biological sciences.

FigShare

Online digital repository where researchers can preserve and share their research outputs, including figures, datasets, images, and videos.

peerj

Preprint server in biology and medicine.

prePrints

A multidisciplinary preprint platform that accepts articles from all fields of science and technology.

arXiv

arXiv is a preprints server in the fields of mathematics, physics, astronomy, computer science, quantitative biology, statistics, and quantitative finance.

Open Access Publishing Platforms

F1000

F1000 open access publishing platform.

WOR

Open access publishing platform for research funded by the Welcome Trust.

plos

PLOS was founded as a nonprofit Open Access publisher, innovator and advocacy organization with a mission to accelerate progress in science and medicine by leading a transformation in research communication.  

bmc

A pioneer of open access publishing, BMC has an evolving portfolio of high quality peer-reviewed journals.  

38-gates

Gates Open Research is a platform for rapid author-led publication and open peer review of research.