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Unpaywall vs CORE

AI Research tools comparison · Updated 2026

Choosing between Unpaywall and CORE? Both are popular AI Research tools. Unpaywall is free to use and focuses on Browser extension. CORE is free to use and specializes in 250M+ metadata records. Here's a detailed side-by-side comparison to help you decide.

At a Glance

Unpaywall CORE
Category AI Research AI Research
Pricing free free
Starting Price Free Free
Best For open-access, browser-extension, free open-access, research, text-mining
Features 6 listed 6 listed

Unpaywall

Free browser extension that finds legal open access versions of paywalled papers.

AI Research free
VS

CORE

World's largest open access paper aggregator with 250M+ records and text mining API.

AI Research free

Feature Comparison

Unpaywall CORE
Browser extension 250M+ metadata records
Open access detection Full-text access
50,000+ source repositories Open access aggregation
DOI-based lookup API for text mining
Green lock indicator Dataset services
API access Repository dashboard

Pricing Comparison

Unpaywall

free

Completely free browser extension. Data feed available for institutions.

CORE

free

Free for individuals. API access free for research. Commercial API licensing available.

Pros & Cons

Unpaywall

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

CORE

Pros
  • + Largest open access collection
  • + Full-text availability
  • + Free API for research
  • + Great for text mining
Cons
  • Interface not very modern
  • Duplicate records possible
  • Search relevance can be poor
  • Full-text not always available

The Verdict

Both Unpaywall and CORE are strong AI Research tools. Unpaywall stands out for Completely free, making it ideal if that's your priority. CORE excels at Largest open access collection, which may be more important for your workflow.

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