Free Open Data APIs — ranked by value

Reference, knowledge & open datasets

Scores rate free-tier value on a 1–10 scale. How scores work →

World Bank Open Data API Open Data No auth Programmatic access to thousands of development indicators (GDP, population, poverty, health) for 200+ countries and aggregates. Fair use
REST Countries Open Data No auth Returns rich data on 250+ countries: names, codes, capitals, currencies, languages, borders, flags and population. No published cap
Wikipedia / MediaWiki API Open Data No auth Query Wikipedia article content, summaries, search, page metadata and revisions across all language editions. 200 req/sec
Wikidata Open Data No auth Collaboratively edited structured knowledge base with REST entity access and a SPARQL query endpoint over linked data. 60/min
DBpedia Open Data No auth Structured knowledge extracted from Wikipedia, queryable via a public SPARQL endpoint and Linked Data interfaces. Fair use
OpenCorporates Open Data API key The largest open database of companies and corporate officers, searchable by jurisdiction across many countries. Free (non-commercial)
data.gov (api.data.gov) Open Data API key Gateway and shared key service for hundreds of U.S. federal government open datasets and agency APIs. 1k req/hr
Numbers API Open Data No auth Returns interesting trivia, math, date and year facts about any number as plain text or JSON. No published cap
Open Library Open Data No auth Open bibliographic data for millions of books: search, editions, authors, covers and ISBN lookups. Free and keyless
Datamuse Open Data No auth Word-finding query engine for synonyms, rhymes, related words, spelling suggestions and autocomplete. 100k req/day
USGS Earthquake Catalog Open Data No auth Real-time and historical earthquake event feeds and FDSN query API from the U.S. Geological Survey. Fair use
Nobel Prize API Open Data No auth Open data on Nobel Prizes and laureates since 1901, including categories, motivations and biographical details. No published cap
OpenSanctions Open Data API key Consolidated open data on sanctioned entities, politically exposed persons and crime, with search and entity-matching endpoints. Free (non-commercial)
OECD Data API Open Data No auth SDMX-based API providing free programmatic access to OECD economic, social and environmental statistics. Fair use
Eurostat Open Data No auth Official European Union statistics across economy, population, trade and environment via JSON and SDMX web services. 50 req/sec
Internet Archive (Archive.org) Open Data No auth APIs for searching and retrieving items, metadata and the Wayback Machine snapshots from the Internet Archive. Fair use
Socrata Open Data API (SODA) Open Data API key Standardized API powering thousands of government and NGO open datasets with SoQL querying over each resource. Per-app/user caps
CKAN / data.gov.uk Open Data No auth CKAN-powered open data portal API for discovering and querying UK government datasets and resources. Fair use
Nager.Date Public Holidays Open Data No auth Worldwide public holiday data by country and year, plus long-weekend and working-day lookups. No published cap
REST Countries Universities (Hipo) Open Data No auth Open dataset and search endpoint for university names, countries and web domains worldwide. No published cap
Open Food Facts Open Data No auth Crowdsourced open database of food products with ingredients, nutrition facts and labels searchable by barcode. 100 req/min
PatentsView Open Data API key Query and visualize US patent data including inventors, assignees, citations and technology trends. 45 req/min
OpenAlex Open Data No auth Fully open index of scholarly works, authors, institutions, venues and concepts, free and key-less. 100k req/day
Callook.info (Ham Radio) Open Data No auth Look up United States amateur radio callsign data from the FCC license database as JSON. No published cap