✓
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
CORE
AI Research
Free
✓
Mar 2026
→
World's largest open access paper aggregator with 250M+ records and text mining API.
Best for: open-access
BASE Search
AI Research
Free
✓
Mar 2026
→
Academic search engine indexing 300M+ open access documents from 10,000+ providers.
Best for: research
Kopernio
AI Research
Free
✓
Mar 2026
→
Clarivate browser extension for one-click PDF access to research papers via library links.
Best for: browser-extension