Open Access Helper (OAHelper) helps you to find legal Open Access copies of scientific publications. It is intended to combat the problem that although there are more than 50 million Open Access versions of scientific articles hiding behind paywalls, these are difficult to find. The Open Access Helper exists in various versions, as a mobile app as well as a desktop version and as a browser extension for Chrome, Edge, Safari and Firefox.

The Open Access Helper is based on the data from: Unpaywall, CORE, Open Access Button,  OpenAlex, OpenCitations.net, europepmc.org and Retraction Watch (CrossRef).