Unpaywall
Free browser extension that finds legal open access versions of paywalled papers.
About Unpaywall
Free browser extension that automatically finds legal open access versions of research papers as you browse. Harvests open access content from 50,000+ repositories and journals. Shows a green lock icon when a free version is available.
Key Features
- Browser extension
- Open access detection
- 50,000+ source repositories
- DOI-based lookup
- Green lock indicator
- API access
Pricing
free
Completely free browser extension. Data feed available for institutions.
Pros
- Completely free
- Works automatically while browsing
- Legal open access only
- Simple one-click access
Cons
- Only finds already-open papers
- Not all papers have OA versions
- Browser extension only
- No search functionality