Unpaywall
Free browser extension that finds legal open access versions of paywalled papers.
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Why choose 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.
- Completely free
- Works automatically while browsing
- Legal open access only
- Simple one-click access
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Where it falls short
- Only finds already-open papers
- Not all papers have OA versions
- Browser extension only
- No search functionality
03
Best for these users
Target audience
Researchers, academics, knowledge workers
Best for
Completely free
Skip if you need
Only finds already-open papers
04
Pricing overview
Free
Free plan: Yes
Completely free browser extension. Data feed available for institutions.
Check current pricing →
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Key features
✓Browser extension
✓Open access detection
✓50,000+ source repositories
✓DOI-based lookup
✓Green lock indicator
✓API access
07
Alternatives to Unpaywall
BASE Search
Academic search engine indexing 300M+ open access documents from 10,000+ providers.
free
Compare →
08
Related comparisons
09
The verdict
Unpaywall
Free
Unpaywall is a solid choice for researchers who need completely free. At free, it delivers good value. Main caveat: only finds already-open papers. Compare with alternatives before committing.