OpenAlex API
Free OpenAlex API with no key: 250M+ scholarly works, authors, institutions, topics and citation graph. The open replacement for Microsoft Academic. Tested.
Endpoint tested and returned HTTP 200 on 20 Aug 2026
What is the OpenAlex API?
OpenAlex is a free, key-free API cataloguing more than 250 million scholarly works along with authors, institutions, sources, topics and the citation graph connecting them — an open replacement for the discontinued Microsoft Academic Graph.
OpenAlex goes beyond bibliographic records to model the whole scholarly ecosystem as linked entities: works cite works, authors belong to institutions, works have topics. That graph structure is what makes it useful for research analytics rather than simple lookup.
Its group-by aggregation is genuinely powerful — you can ask for counts of works grouped by publication year, institution or open-access status in one request, which would otherwise require paging through millions of records.
Quick facts
- Base URL
https://api.openalex.org- Authentication
- No API key. Adding `mailto=` joins the faster polite pool, as with Crossref.
- Rate limit
- 100,000 requests per day and 10 per second, which is generous.
- Pricing
- Free and fully open — the entire dataset is also downloadable.
- CORS
- Enabled — callable directly from browser JavaScript
- Official docs
- Read the docs
How to use the OpenAlex API
Every request below was executed against the live API on 20 Aug 2026, and the response shown is the real body it returned — not an illustration.
1. Query scholarly works
GET https://api.openalex.org/works?per-page=1
curl 'https://api.openalex.org/works?per-page=1'const res = await fetch("https://api.openalex.org/works?per-page=1");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);import requests
res = requests.get("https://api.openalex.org/works?per-page=1", timeout=20)
res.raise_for_status()
print(res.json()){
"meta": {
"count": 322044938,
"db_response_time_ms": 150,
"page": 1,
"per_page": 1,
"groups_count": null,
"x_query": {
"oql": "works",
"oqo": {
"get_rows": "works"
},
"url": "/works?per_page=1"
},
"cost_usd": 0.0001
},
"results": [
{
"id": "https://openalex.org/W3038568908",
"doi": "https://doi.org/10.1585/pfr.15.2402039",
"title": "Radiation Resistant Camera System for Monitoring Deuterium Plasma Discharges in the Large Helical Device",
"display_name": "Radiation Resistant Camera System for Monitoring Deuterium Plasma Discharges in the Large Helical Device",
"publication_year": 2020,
"publication_date": "2020-06-08",
"ids": {
"openalex": "https://openalex.org/W3038568908",
"doi": "https://doi.org/10.1585/pfr.15.2402039",
"mag": "3038568908"
},
"language": "en",
"primary_location": {
"id": "doi:10.1585/pfr.15.2402039",
"is_oa": true,
"landing_page_url": "https://doi.org/10.1585/pfr.15.2402039",
"pdf_url": "https://www.jstage.jst.go.jp/article/pfr/15/0/15_2402039/_pdf",
"source": {
"id": "https://openalex.org/S46033839",
"display_name": "Plasma and Fusion Research",
"issn_l": "1880-6821",
"issn": [
"1880-6821"
],
"is_oa": true,
"is_in_doaj": false,
"is_core": true,
"host_organization": "https://openalex.org/P4328135220",
"host_organization_name": "Japan Society of PlasParameters
| Parameter | Type | Required | Description |
|---|---|---|---|
per-page | integer | Optional | Results per page, max 200. 25 |
page / cursor | string | Optional | Pagination; cursor for deep paging. * |
search | string | Optional | Full-text search across works. climate change |
filter | string | Optional | Filters such as publication_year or is_oa. publication_year:2026 |
group_by | string | Optional | Aggregate counts by a field instead of listing works. publication_year |
mailto | string | Optional | Your email, for the polite pool. you@example.com |
Response fields
meta.countinteger- Total works matching the query.
results[].idstring- OpenAlex entity URL, the canonical identifier.
results[].doistring- DOI where one exists.
results[].titlestring- Work title as a plain string, unlike Crossref.
results[].authorshipsarray- Authors with institution affiliations.
results[].cited_by_countinteger- Citation count.
results[].open_accessobject- Open access status and best available URL.
results[].topicsarray- Classified research topics with confidence scores.
What you can build with the OpenAlex API
- Build research analytics and bibliometric dashboards
- Analyse institutional publication output and collaboration
- Find open-access versions of paywalled papers
- Map research topics and citation networks
Common errors and how to fix them
403 or throttling
Anonymous pool under load.
Fix: Add mailto= to join the polite pool; it is free and noticeably more reliable.
Deep paging fails
Page-based paging is capped.
Fix: Use cursor=* and follow meta.next_cursor for large result sets.
Filter syntax errors
Filters use colon-separated field:value pairs joined by commas.
Fix: For example filter=publication_year:2026,is_oa:true.
OpenAlex API — frequently asked questions
Is OpenAlex free?
Yes, completely free and open with no API key, at 100,000 requests per day. The entire dataset is also available as a downloadable snapshot.
How is it different from Crossref?
Crossref is authoritative for DOI metadata. OpenAlex models the wider scholarly graph — authors, institutions, topics and citations as linked entities — which suits analytics rather than pure lookup.
What replaced Microsoft Academic Graph?
OpenAlex was built explicitly as its open successor after Microsoft discontinued MAG in 2021.
Can I aggregate without downloading everything?
Yes, group_by returns counts grouped by a field such as publication_year or institution in a single request — a major advantage over paging.
Tools that pair with this API
JSON Formatter
Format, beautify and minify JSON online with 2-space, 4-space or tab indentation. Sort keys alphabetically and catch syntax errors instantly — free and private.
CSV to JSON Converter
Convert CSV to a JSON array of objects online. Header-row detection, comma/semicolon/tab delimiters and pretty-printed output — 100% in your browser.
Alternatives to OpenAlex API
If OpenAlex does not fit, these science & space apis cover similar ground. Every one was called before publishing, and each links to its own reference page with a working curl command and the response it returned.
| API | What it does | Auth | CORS | Last verified |
|---|---|---|---|---|
| NASA APOD | Free NASA Astronomy Picture of the Day API. Daily space images with expert explanations, HD URLs and archive access back to 1995. Tested curl example. | Key | Yes | 19 Aug 2026 |
| Open Notify ISS | Free API returning the International Space Station's live latitude and longitude. No key, updates in real time. Tested curl example and live JSON response. | No key | Yes | 19 Aug 2026 |
| USGS Earthquake | Free USGS earthquake API with no key: live global seismic events as GeoJSON, filterable by magnitude, time and location. Tested curl example and live response. | No key | Yes | 19 Aug 2026 |
| Launch Library 2 | Free rocket launch API with no key: upcoming and past launches from every space agency, with rockets, missions, pads and live stream links. Tested example. | No key | Yes | 19 Aug 2026 |
| OpenCitations | Free OpenCitations API with no key: open citation data linking DOIs — who cites whom, with timespans. An open alternative to proprietary citation indexes. Tested. | No key | Yes | 20 Aug 2026 |
| OPSIN | Free OPSIN web service at EMBL-EBI with no key: parse systematic IUPAC chemical names into SMILES, InChI or CML algorithmically. Open source, deterministic, no lookup table. | No key | Yes | 21 Aug 2026 |
OpenAlex is an independent third-party service and is not affiliated with ByteTools or ByteVancer. Details on this page were verified on 20 Aug 2026; always check the official documentation before relying on this API in production, as terms and limits can change.