Sci-Hub

Offers direct access to over 64.5 million academic papers by bypassing paywalls using institutional proxies.

Z-Library

A large repository of books and articles, with user-contributed content, aiming to be the world's largest e-book and scientific paper library.

Library Genesis

Aggregates scientific, technical, and academic content, offering links to third-party resources.

Unpaywall

Harvests open-access content from numerous publishers and repositories, providing easy access to free versions of research papers.

GetTheResearch.org

An AI-powered search engine for free scholarly articles, part of the Unpaywall project.

Directory of Open Access Journals (DOAJ)

Indexes nearly 17,500 open-access journals across various disciplines.

Researcher

A mobile app that provides daily updates on new journal papers relevant to your research.

ScienceOpen

A discovery platform offering advanced search, post-publication peer review, and social sharing features.

OA.mg

A search engine for academic papers, helping users find specific papers or research from various fields.

Internet Archive Scholar

A full-text search index with over 25 million research articles and scholarly documents preserved in the Internet Archive.

Citationsy Archives

A citation management tool with a clean interface and a focus on usability.

CORE

The world’s largest aggregator of open-access research papers from repositories and journals.

Dimensions

A comprehensive research database linking publications to grants, datasets, clinical trials, and patents.

PaperPanda

A Chrome extension that searches for free PDFs of research papers by querying various open-access repositories.