OpenAlex is a free, fully open catalog of the global research system — works, authors, institutions, and the other entities that make up scholarly output — built and maintained by the nonprofit OurResearch. Unlike Scopus or Web of Science, there is no subscription: the underlying dataset is licensed CC0 and can be queried through a REST API or downloaded in bulk. For research administrators evaluating tools for a CRIS, an institutional analytics dashboard, or a research-impact report, OpenAlex is increasingly the infrastructure layer other systems build on rather than just another search box for researchers.
This guide covers what OpenAlex actually is, the real history of its succession from Microsoft Academic Graph, its core data entities, how its API and bulk-download model work (including a real, recent pricing change), and why its open licensing specifically matters for an institution building its own research-information systems.
What OpenAlex Is
OpenAlex is a bibliographic and scholarly-metadata index — named after the ancient Library of Alexandria — that catalogs scholarly works and links them to the people, organizations, journals, publishers, and funders behind them. It is built and stewarded by OurResearch, a Vancouver-based 501(c)(3) nonprofit founded in 2011 that also builds Unpaywall, the open-access-detection tool many library discovery layers and browser extensions already rely on. OpenAlex’s own funding has come in significant part from the Arcadia Fund, a charitable foundation that has backed several pieces of open scholarly infrastructure.
Two things distinguish OpenAlex from most bibliographic databases a research office has historically paid for:
- The data is CC0-licensed. There is no copyright claim on the metadata itself, so it can be downloaded, redistributed, remixed, and built into another product without a license negotiation.
- OurResearch is a signatory to the Principles of Open Scholarly Infrastructure (POSI) — a governance commitment covering open data, open source code, and a sustainability model that doesn’t depend on the data itself ever becoming restricted. OurResearch was among the earliest organizations to make this commitment, in 2021, and reaffirmed it after POSI’s version 2.0 update.
From Microsoft Academic Graph to OpenAlex: A Real Succession, Not a Rebrand
OpenAlex exists in its current form because of a specific, verifiable event: in May 2021, Microsoft announced it would fully retire Microsoft Academic Graph (MAG) and the associated Microsoft Academic search service by the end of that year. MAG had been a widely used free bibliographic dataset since 2016, and its planned shutdown left a real infrastructure gap for anyone who had built tooling on top of it. OurResearch had already been developing a MAG-adjacent index; when Microsoft’s shutdown was confirmed, OurResearch incorporated the final MAG data dump (excluding patent data) as a starting corpus and launched OpenAlex on January 1, 2022 — timed to go live essentially as MAG went dark, positioned explicitly as a free, open, ongoing replacement rather than a one-time archive of MAG’s final snapshot.
This history matters practically, not just trivially: any institutional tooling, citation-matching script, or analytics pipeline still referencing Microsoft Academic identifiers is referencing a dataset that has not been updated since 2021. OpenAlex is the actively maintained continuation of that lineage, and its own entity IDs (not MAG IDs) are what current integrations should be built against.
OpenAlex’s Core Entities
OpenAlex organizes everything around a small set of linked entity types, each with its own stable ID and API endpoint. Understanding this entity model is the prerequisite for using OpenAlex as backend data for a CRIS or an analytics build, since it determines what a query can actually join against:
- Works — the core scholarly output records: journal articles, preprints, books, datasets, and similar. Each Work carries metadata (title, authorship, publication venue, open-access status) plus resolved links out to identifiers such as a DOI where one exists.
- Authors — person-level records, disambiguated algorithmically across name variants and, where available, linked to an ORCID iD.
- Sources — the journals, conference proceedings, repositories, and preprint servers that host Works.
- Institutions — universities, hospitals, companies, and other organizations, linked where possible to a ROR ID for unambiguous institutional identification.
- Topics — OpenAlex’s current subject-classification system, developed with Leiden University’s Centre for Science and Technology Studies (CWTS). Roughly 4,500 topics are organized into a four-level hierarchy (domain, field, subfield, topic), assigned to Works through a combination of citation-network clustering and machine classification. Topics superseded OpenAlex’s earlier Concepts field, which OpenAlex now documents as deprecated: Concepts values are still returned on older Work records for backward compatibility, but are no longer actively maintained, and new integrations should use Topics instead.
- Publishers and Funders — organization-level records for the entities that publish Sources or fund the research behind Works, useful for institutional or funder-level reporting rollups.
Every entity links to the others — a Work points to its Authors, its Source, its Authors’ Institutions, its Topics, and any Funders acknowledged in it — which is what makes OpenAlex usable as a graph rather than a flat list of records.
The API and the Bulk-Data Model
OpenAlex is queryable two ways, and the choice between them matters for how an institution actually builds on it:
- The REST API (
api.openalex.org) supports filtering, full-text search across abstracts, and pagination across all seven entity types — the right tool for on-demand lookups, such as resolving a single Work by DOI or pulling a researcher’s current output list. A free account and API key (obtained at openalex.org) is the recommended way to query it. In February 2026, OpenAlex introduced usage-based pricing for API calls: different operations (a bulk search versus a single lookup by ID or DOI) cost different, published amounts, with every API key receiving a modest daily free allowance and single-record lookups by ID or DOI kept free regardless of volume. OurResearch has been explicit that this is a “free data, paid service” model, not a retreat from open access — the API is a hosted convenience layered on top of data that remains unrestricted. - The full snapshot is a complete, periodically refreshed dump of the entire dataset (hundreds of millions of Works and their linked entities), distributed as newline-delimited JSON and Parquet files in a public, anonymously-accessible Amazon S3 bucket — no AWS account, sign-up, or requester-pays charge required to sync it. This is the path an institution building its own local research-analytics database or CRIS backend actually wants: rather than paying per API call at scale, pull the whole graph once, refresh it on a schedule, and query it locally under the same CC0 terms.
The distinction is the same one that shows up in OurResearch’s own framing: the API now has a metered cost structure for heavy, on-demand use, but the underlying data — the actual CC0-licensed content — remains free to download and self-host in full, with no paywall on the dataset itself.
Why Fully Open Licensing Matters for Research Institutions
This is the practical reason OpenAlex shows up repeatedly in CRIS and research-analytics conversations rather than staying a researcher-facing search tool:
- No subscription gate on the underlying data. Scopus and Web of Science require an institutional license just to query their APIs at all, and neither publishes a free, complete, redistributable bulk export of their full metadata under an open license — see CASRAI’s Scopus vs Web of Science vs OpenAlex comparison for how the three actually differ on coverage, cost, and access model. An institution can build a production analytics pipeline on OpenAlex without a procurement cycle.
- CC0 licensing removes redistribution risk. A CRIS vendor, an institutional repository, or a university’s own reporting dashboard can ingest, transform, and re-publish OpenAlex-derived data (institutional publication counts, a faculty member’s output list, a funder-acknowledgment rollup) without navigating a data-use agreement that restricts what can be done with the output.
- The entity model is built for interoperability, not lock-in. Because Works, Authors, and Institutions resolve out to DOIs, ORCID iDs, and ROR IDs — the same identifier infrastructure euroCRIS-aligned CRIS platforms are already built around — OpenAlex data joins cleanly against records an institution already holds from Crossref or DataCite, rather than requiring a separate crosswalk. See CASRAI’s identifier crosswalk guide for how these systems fit together in practice.
- Governance transparency. POSI’s stakeholder-governance principles give institutions a real answer to “what happens if this vendor changes terms or shuts down,” which is a legitimate procurement question for any infrastructure a CRIS depends on — the answer for OpenAlex is closer to “the data ships out the door with you” than it is for a proprietary index.
OpenAlex Compared to Related Tools
OpenAlex gets compared against several different categories of tool, and conflating them is a common source of confusion:
- Scopus and Web of Science are subscription, editorially curated citation indexes with narrower title lists but (for Web of Science specifically) a longer, more selective curation tradition. See the full Scopus vs Web of Science vs OpenAlex comparison.
- Semantic Scholar is a free, AI-powered discovery and search tool built by the Allen Institute for AI — strong on AI-generated summaries and citation-influence classification, and, like OpenAlex, offers an open API. The two are more complementary than competing: some institutions pull structured metadata from OpenAlex and use Semantic Scholar’s NLP-derived features (like TLDR summaries) as a separate enrichment layer.
- Research Rabbit is a citation-mapping discovery layer built on top of open bibliographic graph data rather than an independently curated index in its own right — a different category of tool than OpenAlex (a source-of-record graph) even though both sit in the open-infrastructure ecosystem.
- OpenAIRE Graph is the one most often confused with OpenAlex, since both are free, open, CC0-adjacent scholarly graphs. They are genuinely different infrastructure: OpenAIRE Graph is maintained by the European OpenAIRE initiative, is oriented around European Open Science Cloud (EOSC) compliance and harvesting from CRIS systems under OpenAIRE Guidelines, and is distributed via Zenodo dumps. OpenAlex is a US-nonprofit-maintained, globally scoped index with its own independent entity model and ID system. An institution may reasonably use both for different purposes rather than treating one as a substitute for the other.
Frequently Asked Questions
Is OpenAlex actually free?
The underlying data is free without qualification: it is CC0-licensed and downloadable in full as a bulk snapshot with no account, payment, or usage restriction. The hosted REST API is free for typical use (a daily free allowance per API key, and unlimited free single-record lookups by ID or DOI), with usage-based charges applying only to heavy, high-volume search and filter traffic under the pricing model introduced in February 2026.
What replaced Microsoft Academic Graph?
OpenAlex did, directly. Microsoft announced MAG’s full retirement in May 2021, and OpenAlex launched January 1, 2022, incorporating the final MAG data dump as part of its starting corpus and continuing as an actively maintained index going forward. Any tooling still built against Microsoft Academic identifiers is referencing a dataset frozen since 2021.
What license is OpenAlex’s data released under?
CC0 — a public-domain dedication with no attribution requirement, though citing OpenAlex as a source is good practice and is what most published research using it does anyway.
What are OpenAlex Topics, and how are they different from Concepts?
Topics are OpenAlex’s current subject-classification system: roughly 4,500 topics in a four-level hierarchy (domain, field, subfield, topic), built with Leiden University’s CWTS using citation-network clustering plus machine classification. Topics replaced the earlier Concepts field, which OpenAlex has deprecated — Concepts values remain on older records for backward compatibility but are not actively maintained, so new integrations should classify against Topics.
Does OpenAlex have rate limits, and do I need an API key?
An API key (free to obtain from an OpenAlex account) is the recommended way to query the API and is required to get the full daily free usage allowance under the current pricing model. Simple lookups of a Work by its DOI or OpenAlex ID are free regardless of volume; search and filter operations draw against the daily allowance or, beyond that, a prepaid usage balance.
How is OpenAlex different from OpenAIRE Graph?
Both are free, open scholarly graphs, but they’re built and governed independently: OpenAIRE Graph is a European-initiative project oriented around EOSC compliance and CRIS-system harvesting, distributed via Zenodo; OpenAlex is a globally scoped index maintained by the US nonprofit OurResearch, queryable through its own API and AWS-hosted snapshot. They are not interchangeable, and some institutions draw on both.
