Unpaywall

The Unpaywall REST API gives anyone free, programmatic access to the Unpaywall database of open access scholarly articles. The database covers over 120 million articles with Crossref DOIs and provides free, legal full-text links where available, with metadata on OA status (gold, hybrid, bronze, green), host type (publisher, repository), version (published, accepted, submitted), and license information.

1 APIs 0 Features

Open AccessScholarly ArticlesResearchAcademicLibrariesDOIScience

APIs

Unpaywall API

Free REST API providing open access status and full-text links for 120M+ scholarly articles. Look up any article by DOI to get its OA status, best open access location (publishe...

Semantic Vocabularies

Unpaywall Context

8 classes · 37 properties

JSON-LD

API Governance Rules

Unpaywall API Rules

6 rules · 2 errors 3 warnings 1 info

SPECTRAL

JSON Structure

Unpaywall Article Structure

0 properties

JSON STRUCTURE

Example Payloads

Unpaywall Get Doi Example

2 fields

EXAMPLE

Unpaywall Search Example

2 fields

EXAMPLE

Resources

👥

GitHubOrganization

Sources

aid: unpaywall
name: Unpaywall
description: >-
  The Unpaywall REST API gives anyone free, programmatic access to the Unpaywall database of open access scholarly
  articles. The database covers over 120 million articles with Crossref DOIs and provides free, legal full-text links
  where available, with metadata on OA status (gold, hybrid, bronze, green), host type (publisher, repository), version
  (published, accepted, submitted), and license information.
url: https://raw.githubusercontent.com/api-evangelist/unpaywall/refs/heads/main/apis.yml
created: '2025-02-06'
modified: '2026-05-19'
specificationVersion: '0.19'
type: Index
tags:
  - Open Access
  - Scholarly Articles
  - Research
  - Academic
  - Libraries
  - DOI
  - Science
apis:
  - aid: unpaywall:unpaywall
    name: Unpaywall API
    description: >-
      Free REST API providing open access status and full-text links for 120M+ scholarly articles. Look up any article
      by DOI to get its OA status, best open access location (publisher or repository), license, version, and all
      available free copies. Also supports title-based search across the full database. No API key required — just
      include your email address in requests. Rate limit: 100,000 calls per day.
    humanURL: https://unpaywall.org/products/api
    baseURL: https://api.unpaywall.org/v2
    tags:
      - Open Access
      - DOI
      - Scholarly Articles
      - Search
    properties:
      - type: Documentation
        url: https://unpaywall.org/products/api
      - type: OpenAPI
        url: https://raw.githubusercontent.com/api-evangelist/unpaywall/refs/heads/main/openapi/unpaywall-openapi.yml
      - type: SpectralRules
        url: https://raw.githubusercontent.com/api-evangelist/unpaywall/refs/heads/main/rules/unpaywall-rules.yml
      - type: JSONSchema
        url: >-
          https://raw.githubusercontent.com/api-evangelist/unpaywall/refs/heads/main/json-schema/unpaywall-article-schema.json
common:
  - type: GitHubOrganization
    url: https://github.com/ourresearch
  - type: LinkedIn
    url: https://www.linkedin.com/company/impactstory
  - type: Website
    url: https://unpaywall.org
  - type: Documentation
    url: https://unpaywall.org/products/api
  - type: DataFormat
    url: https://unpaywall.org/data-format
  - type: Support
    url: https://support.unpaywall.org
  - type: Vocabulary
    url: https://raw.githubusercontent.com/api-evangelist/unpaywall/refs/heads/main/vocabulary/unpaywall-vocabulary.yml
  - type: JSONLDContext
    url: https://raw.githubusercontent.com/api-evangelist/unpaywall/refs/heads/main/json-ld/unpaywall-context.jsonld
  - type: LLMsTxt
    url: https://unpaywall.org/llms.txt
maintainers:
  - FN: Kin Lane
    email: kin@apievangelist.com