✓
Tool
Category
Pricing
Free?
Updated
Unpaywall
AI Research
Free
✓
Mar 2026
→
Free browser extension that finds legal open access versions of paywalled papers.
Best for: open-access
Kopernio
AI Research
Free
✓
Mar 2026
→
Clarivate browser extension for one-click PDF access to research papers via library links.
Best for: browser-extension