Unpaywall
Unpaywall
Service that helps researchers locate legal open-access full-text versions of scholarly articles.
Developer:
OurResearch
Our Take
Unpaywall is a practical way to check whether a scholarly article has a legally available open-access version. Its browser extension and data services can help researchers find repository or publisher-hosted copies, making it a useful companion to library databases and citation searches. It is especially convenient when you already have a DOI or are viewing an article landing page behind a paywall.
Coverage depends on the metadata and open-access locations available for each work, so a missing result does not prove that no free copy exists. Check the version and source before citing or sharing a PDF, and follow any applicable license terms. Unpaywall helps locate accessible versions; it does not replace a comprehensive literature search or guarantee that every located copy is the final published article.
Key Features
Open-access location lookup, Repository-version discovery, Browser and API integrations, License and access metadata
Best For
Finding accessible full text
Research Tasks
Find legal full-text alternatives to paywalled articles; collect accessible papers for a literature review; check whether an accepted manuscript is available; identify access routes before requesting a copy.
Pricing
$0 — free access to its open-access lookup API; API requests require an email address and are subject to rate limits (recommended limit: 100,000 calls/day).