- Unpaywall --> https://unpaywall.org/
Install this browser extension on Chrome and read the paper directly on the journal's website legally and for free.
- Open Access Button (OAB) --> https://Inkd.in/ex2kAJ7v
Copy and paste the paper link or DOl on the OAB website. Paper will be accessible on the next page. Legally.
- PaperPanda --> https://paperpanda.app/
Like Unpaywall, this Chrome extension allows you to access millions of research papers in one click.
- DOAJ --> https://doaj.org/
As the name suggests, DOAJ (Directory of Open Access Journals) provides access to millions of scientific papers from around the world for free.
- OAL.]mg --> https://oa.mg/
Like Google that was made specifically to find academic papers.
There are more than 250 million papers available to access.
6.. Core -> https://core.ac.uk/
The largest database of research papers in the world with more than 298 million papers from all over the world that can be accessed for free.
- arXiv --> https://arxiv.org/
Especially for lovers of natural sciences and economics, this website provides access to 2.4 million academic papers for free.
- Tandfonline --> http://www.tandfonline.com
200++ open journals can be access with one click.
- JSTOR https://www.jstor.org/
JSTOR provides access to thousands of academic journals, books, and primary sources in various disciplines. While not entirely free, JSTOR offers limited access to content without a subscription, making it a partial alternative to Sci-Hub.