Unpaywall
Unpaywall, operated by nonprofit OurResearch, maintains an open database of 56+ million free scholarly articles harvested from 50,000+ publishers and repositories, serving academic libraries, citation indices, discovery platforms, researchers, and research funders via REST API, browser extension, and premium Data Feed subscriptions.
- Company typePrivate
- Founded2017
- HeadquartersSanford, United States
- Headcount1–10
- GTM typeB2B
- OfferingSoftware
What Unpaywall does
Unpaywall is an open database of free scholarly articles operated by OurResearch (the nonprofit d/b/a of Impactstory, Inc.), headquartered in Sanford, North Carolina. The organization maintains a continuously updated index of 56.3 million open access article records harvested from 50,000+ publishers and repositories worldwide, out of a total database of approximately 120 million article records. The dataset uses first- and second-generation hybrid detection methods to classify articles by OA type (Gold, Hybrid, Bronze, Green, Closed) with priority-ranked location objects that favor publisher-hosted content and authoritative repositories. Core products include a free REST API (rate-limited to 100,000 calls per day), a browser extension for Chrome and Firefox with 600,000+ users, database snapshots, a Simple Query Tool, and a beta Article Search across all 120M records. A premium Data Feed subscription, the company's only monetized offering, provides daily/weekly changefiles and updated snapshots to enterprise customers on custom contract terms. The team consists of three people: Richard Orr, Heather Piwowar, and Jason Priem. Unpaywall data is integrated into thousands of downstream systems globally, including major citation indices (Dimensions, Scopus, Web of Science), discovery platforms (EBSCO, OCLC WorldCat, ProQuest), library link resolvers (SFX, 360 Link), and AI/ML research tools (Semantic Scholar, Scholarcy). Additional tools include Unsub, a library subscription decision-support product that won 'Most Impactful New Product' at the 2019 Charleston Conference. Unpaywall received $850,000 in funding from Arcadia Funds in July 2018 and was featured in Nature in August 2018 as transforming Open Science. The organization is mission-driven rather than profit-maximizing, and the parent OurResearch also operates OpenAlex, indicating a broader portfolio of scholarly communication infrastructure.
Unpaywall firmographics
Firmographics- Name
- Unpaywall
- Legal name
- Impactstory, Inc.
- Website
- https://unpaywall.org
- Company type
- Private
- Founded year
- 2017
- Operating status
- Operating
- Headcount range
- 1–10 employees
- Short description
- Unpaywall, operated by nonprofit OurResearch, maintains an open database of 56+ million free scholarly articles harvested from 50,000+ publishers and repositories, serving academic libraries, citation indices, discovery platforms, researchers, and research funders via REST API, browser extension, and premium Data Feed subscriptions.
- Ownership category
- akta.pro rank
Unpaywall industry classification
Industry- Product category
- Open Access Scholarly Database
- NAICS
- Web Search Portals, Libraries, Archives, and Other Information Services (519), Web Search Portals and All Other Information Services (51929), Software Publishers (513210)
- SIC
- Periodicals: Publishing Or Publishing & Printing (2721)
- akta.pro primary industry
- OER Repositories, Discovery & Metadata Services (EDAGAJAL)
- akta.pro secondary industries
- Digital Archives, Libraries & Institutional Access Platforms (MPAJAMAJ), Open Access Scholarly Journals & Monographs (EDAGAFAJ)
Keywords
Where Unpaywall is headquartered
LocationHeadquarters
- HQ city
- Sanford
- HQ country
- United States
- HQ region
- North America
Offices1 record
Markets served
Unpaywall business model
Business model- GTM type
- B2B
- Offering type
- Software
- Cost components
- Technology or R&D, Personnel, Infrastructure, Operations
Revenue model
- REST API Access: Free programmatic access to the Unpaywall database via REST API. Rate limited to 100,000 calls per day. This is the primary free tier that enables broad adoption among developers, researchers, and institutions.
- Data Feed Subscription: Premium subscription providing daily and weekly changefiles reflecting database changes, plus access to current snapshot updated daily (all 120M rows). The Data Feed is the only paid product as ongoing harvesting is more expensive than one-time snapshot downloads. Pricing is handled on a custom basis based on organization size and intended use.
- Browser Extension: Free browser extension for Chrome and Firefox with 600,000+ users. Acts as a product-led growth tool driving awareness and adoption of the open access mission without direct monetization.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Freemium | Others | Free access to database via REST API, snapshot downloads, and Simple Query Tool |
| Subscription | Monthly | Data Feed subscription for enterprise-level ongoing database updates |
Go-to-market motion2 records
Distribution channels5 records
Marketing channels5 records
Unpaywall product offering
Product offeringCore offering
Unpaywall operates the world's largest open database of free scholarly articles, containing 56+ million records harvested from over 50,000 publishers and repositories worldwide. The organization delivers this data through multiple channels including a free REST API, a browser extension with 600,000+ users, a database snapshot, a premium Data Feed subscription, and integrations into thousands of downstream systems used by libraries, citation indices, and discovery platforms.
Product overview
Unpaywall is a portfolio of open access scholarly article discovery and delivery tools, comprising a core open database of 56+ million free scholarly articles harvested from over 50,000 publishers and repositories. The product suite includes free offerings (Browser Extension with 600,000+ users, REST API, Simple Query Tool, Article Search beta) and a premium Data Feed subscription service. The ecosystem extends through integrations with thousands of library systems, discovery platforms, and information products worldwide, including major citation indices (Dimensions, Scopus, Web of Science), discovery tools (EBSCO, OCLC, ProQuest), library link resolvers (SFX, 360 Link), and other OA tools. Unpaywall is a nonprofit project of OurResearch (Impactstory, Inc.) with all source code openly available.
Differentiator
Problem solved
Functional benefit
Products and services
- Browser Extension Free Chrome and Firefox browser extension that automatically detects free open access versions of scholarly articles when users visit paywalled papers, displaying a green tab indicator to provide instant legal free access; used by 600,000+ researchers, academics, and students.
- REST API Free programmatic REST API (v2) providing access to the Unpaywall database with DOI lookup (GET /v2/:doi) and title search (GET /v2/search?query=:your_query) endpoints; returns JSON data using the same schema as the snapshot and Data Feed; rate limited to 100,000 calls per day; targeted at developers, researchers, and institutions.
- Data Feed Premium subscription providing daily and weekly changefiles reflecting database updates, plus access to the current daily-updated snapshot of all 120M rows; the only paid Unpaywall product, with custom pricing based on organization size and intended use; targeted at enterprises needing ongoing synchronization of their local databases.
- Database Snapshot Free full database download containing all 120M rows of article records with OA location data; recommended for users needing more than 100,000 API calls per day or wanting local access; now distributed as the OpenAlex snapshot updated monthly.
- Simple Query Tool Free web-based tool that allows users to check up to 500 DOIs at once for Open Access status, processing the batch through the API and returning results in CSV and JSON formats; targeted at researchers and information professionals doing bulk lookups.
- Article Search Beta search tool to search all 120M articles in the Unpaywall database by title, with the option to filter for free-to-read articles only; accessible via the REST API search endpoint.
- Unsub Library subscription decision-support tool that mashes up journal-level Open Access data with institutional citation patterns and COUNTER download information to forecast the impact of cancellation or subscription decisions on library costs and article fulfillment; targeted at academic libraries making Big Deal and journal subscription decisions.
- Library Link Resolver Integration Integration into library link resolvers including SFX, 360 Link, and EBSCO FTF, allowing library users to be served OA copies when no subscription access is available; used by over 1,000 libraries worldwide; enables libraries to enhance patron access at the point of need.
Quantifiable outcome
- Users read 52% of research papers for free using the Unpaywall browser extension
- +4 more outcomes
Companies that use Unpaywall
Customer profileNamed customers15 records
Segments5 records
Ideal customer profiles4 records
Unpaywall technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- Yes
- API docs
- API detail
Core technology
AI maturity
App detail
Integration44 records
AI capability2 records
Feature5 records
Unpaywall partnerships and signals
Strategic signalPartnerships
17 partnerships are on record, tiered core and flagship.
- DimensionscoreCitation index platform integrating Unpaywall data for open access discovery, allowing users to filter publications by open access status using Unpaywall's comprehensive dataset.
- Scopus (Elsevier)coreElsevier's Scopus citation index integrates Unpaywall data to enhance open access visibility within its academic search platform.
- Web of SciencecoreClarivate's Web of Science incorporates Unpaywall open access data to enhance publication discovery and OA status information.
- EBSCO Discovery SystemcoreEBSCO's discovery service integrates Unpaywall for open access article links, serving thousands of libraries through the EDS platform.
- OCLC WorldCat DiscoverycoreWorldCat Discovery enhanced with Unpaywall Open Access DOI links, providing open content discovery within OCLC's library discovery system.
- ProQuest (Alma, Primo, Summon)coreProQuest's library service platforms (Alma, Primo, and Summon) integrate Unpaywall for open access article discovery.
- PubMed Central / Europe PubMed CentralcoreEuropean PubMed Central integrates Unpaywall data to enhance open access discovery within the PubMed biomedical literature search system.
- ZoterocoreReference manager with improved PDF retrieval through Unpaywall integration, helping researchers automatically find open access versions of cited articles.
- Semantic ScholarcoreAI-powered academic search engine from the Allen Institute for AI using Unpaywall data to surface open access versions of research papers.
- US National Institutes of Health (NIH)flagshipUsing Unpaywall to track the openness of funded research and improve efforts to promote Open Access compliance among NIH grant recipients.
- The Wellcome TrustflagshipUsing Unpaywall to help track the openness of research funded by Wellcome and support open access mandates.
- CrossrefcoreUnpaywall uses Crossref metadata, particularly license information, as a data source for identifying and classifying open access content.
- DOAJ (Directory of Open Access Journals)coreUnpaywall uses DOAJ as a data source to identify fully open access journals and verify Gold OA status.
- PubMed CentralcoreNCBI's PubMed Central repository data is used by Unpaywall as a source for OA content identification and verification.
- OpenAIREcoreEuropean open science infrastructure providing DOIBoost integration with Unpaywall to automatically link DOIs to open access versions.
- LibKey NomadcoreBrowser extension from Third Iron integrating Unpaywall data to help users access open access articles at their library's subscribed publishers.
- BrowzinecoreArticle reading platform from Third Iron integrating Unpaywall for discovering open access versions of journal articles.
Scale indicators8 records
Recent moves6 records
Expansion highlights6 records
Unpaywall competitors and assessment
Company assessmentDirect peers
- BASE (Bielefeld Academic Search Engine): Operated by Bielefeld University Library; one of the world's largest open access search engines harvesting from repositories — directly comparable as a free OA discovery layer.
- OpenAlex: Open scholarly graph also operated by OurResearch/Impactstory; the most direct comparator and increasingly a substitute for Unpaywall's bibliographic layer.
- DOAJ (Directory of Open Access Journals): Curated registry of fully OA journals; Unpaywall uses DOAJ as a Gold OA source while competing to be the broader discovery layer for free scholarly content.
- CORE: UK-based aggregator of open access research outputs from repositories worldwide; directly comparable as a free scholarly content discovery and delivery service.
- OpenCitations: Open scholarly citation data infrastructure run by a research group; comparable nonprofit open scholarly metadata mission with similar data-pipeline approach.
- Open Access Button: Browser tool and discovery service for free scholarly articles; uses Unpaywall as a backend and competes as a user-facing open access delivery channel.
Broad incumbents
- Crossref: Foundational DOI and publisher metadata registry; Unpaywall depends on Crossref as a primary upstream data source and competes with it on enriched open metadata.
- Dimensions: Digital Science's citation and research analytics database; integrates Unpaywall data and competes for institutional research analytics budgets.
Emerging players
- Semantic Scholar: AI-powered academic search engine from the Allen Institute for AI; uses Unpaywall data and competes for end-user attention as a discovery surface for free papers.
- Lens.org: Open scholarly search and analytics platform integrating Unpaywall; competes as an OA-aware discovery and patent/scholarly analytics destination.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat5 records
Key risks6 records
Key highlights7 records
Customer concentration
Unpaywall social profiles
Digital presenceUnpaywall financial estimates
Financial estimateRevenue estimate
Valuation estimate
Unpaywall leadership team
Management profileNumber of profiles
Profiles3 records
Unpaywall funding detail
Funding detailFunding overview
Funding rounds1 record
Investors1 record
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
Unpaywall M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about Unpaywall
What does Unpaywall do?
Unpaywall operates the world's largest open database of free scholarly articles, containing 56+ million records harvested from over 50,000 publishers and repositories worldwide. The organization delivers this data through multiple channels including a free REST API, a browser extension with 600,000+ users, a database snapshot, a premium Data Feed subscription, and integrations into thousands of downstream systems used by libraries, citation indices, and discovery platforms.
Is Unpaywall a public or private company?
Unpaywall is a private company. It is classified as nonprofit foundation owned and is currently operating.
When was Unpaywall founded?
Unpaywall was founded in 2017. It employs 1 to 10 people.
Where is Unpaywall based?
Unpaywall is headquartered in Sanford, United States, in the North America region.
How does Unpaywall make money?
Three revenue lines are on record. REST API Access are the primary driver. The others are data Feed Subscription and browser Extension.
Who are Unpaywall's main competitors?
Direct peers on record are BASE (Bielefeld Academic Search Engine), OpenAlex, DOAJ (Directory of Open Access Journals), CORE, OpenCitations and Open Access Button. Broad incumbents are Crossref and Dimensions. Emerging players are Semantic Scholar and Lens.org.
Does Unpaywall have an API?
Yes. The REST API provides free, programmatic access to the Unpaywall database. Version 2 is the current and only supported version. Requests require email as a parameter: api.unpaywall.org/my/request?email=YOUR_EMAIL. Rate limits are 100,000 calls per day. The API accepts DOI lookups via GET /v2/:doi and search via GET /v2/search?query=:your_query. The response uses the same JSON schema as the database snapshot and Data Feed. There is also an R client wrapper available via CRAN (roadoi package). Developer documentation is at unpaywall.org/products/api.
What industry is Unpaywall in?
Unpaywall's product category is Open Access Scholarly Database. Its primary akta.pro industry code is EDAGAJAL, OER Repositories, Discovery & Metadata Services, with a secondary code of MPAJAMAJ, Digital Archives, Libraries & Institutional Access Platforms. Its NAICS code is 519 and its SIC code is 2721.