Census & Demographics APIs
Official statistics offices form the core: Census.gov for US demographic and geographic data, ONS for UK Census 2021 figures, and national databases from Germany, Brazil, Mexico and Sweden. Data USA wraps US census data in a simpler query by state and year, without a key. A separate group predicts demographics from a first name: Genderize.io, Agify.io and Nationalize.io estimate gender, age and nationality.
| API | Pricing | Auth | Format | Free tier | Status |
|---|---|---|---|---|---|
Agify.ioPredicts a likely age for a first name from statistics on roughly a billion people. Data & Knowledge › Census & Demographics | Freemium | API key | JSON | <100/day | Degraded |
Census.govUS Census Bureau demographic, economic and geographic data (ACS, decennial census, and more) by area. Data & Knowledge › Census & Demographics | Free | API key | JSON | Unlimited | Untested |
Data USAUS Census/government data — population, jobs, education, industry — queryable by state and year. Data & Knowledge › Census & Demographics | Free | None | JSON | Unlimited | Live |
Genderize.ioPredicts likely gender for a first name using a database of over 1 billion people. Data & Knowledge › Census & Demographics | Freemium | API key | JSON | <100/day | Degraded |
GENESIS-OnlineGermany's official statistics database covering economy, population and society via a REST/JSON web service. Data & Knowledge › Census & Demographics | Free | JSON | — | Untested | |
IBGEBrazil's statistics agency: geographic divisions, census counts, and aggregated economic indicators. Data & Knowledge › Census & Demographics | None | JSON | Unlimited | Live | |
NameGenderPredicts gender and confidence from a first name, full name, email address, or username. Data & Knowledge › Census & Demographics | Freemium | API key | JSON | 100–1k/day | Live |
Nationalize.ioEstimates a person's likely nationality (ranked country probabilities) from their first name. Data & Knowledge › Census & Demographics | Freemium | API key | JSON | <100/day | Degraded |
ONS API (Office for National Statistics)UK official statistics and Census 2021 data: population, households, labour market and prices by area. Data & Knowledge › Census & Demographics | Free | None | JSON | 10k+/day | Live |
Open Government, MexicoMexico's national statistics API: economic, demographic and geographic indicators by state and municipality. Data & Knowledge › Census & Demographics | Free | API key | JSON | Unlimited | Untested |
Open Government, SwedenStatistics Sweden's official statistical database API: population, economy, labour market and more. Data & Knowledge › Census & Demographics | Free | None | JSON | — | Live |
Agify.ioFreemiumDegraded
Predicts a likely age for a first name from statistics on roughly a billion people.
API key · JSON
<100/day
llms.txt
Census.govFreeUntested
US Census Bureau demographic, economic and geographic data (ACS, decennial census, and more) by area.
API key · JSON
Unlimited
no machine-readable spec
Data USAFreeLive
US Census/government data — population, jobs, education, industry — queryable by state and year.
None · JSON
Unlimited
no machine-readable spec
Genderize.ioFreemiumDegraded
Predicts likely gender for a first name using a database of over 1 billion people.
API key · JSON
<100/day
llms.txt
GENESIS-OnlineFreeUntested
Germany's official statistics database covering economy, population and society via a REST/JSON web service.
· JSON
—
no machine-readable spec
IBGELive
Brazil's statistics agency: geographic divisions, census counts, and aggregated economic indicators.
None · JSON
Unlimited
no machine-readable spec
NameGenderFreemiumLive
Predicts gender and confidence from a first name, full name, email address, or username.
API key · JSON
100–1k/day
OpenAPI spec · llms.txt
Nationalize.ioFreemiumDegraded
Estimates a person's likely nationality (ranked country probabilities) from their first name.
API key · JSON
<100/day
llms.txt
ONS API (Office for National Statistics)FreeLive
UK official statistics and Census 2021 data: population, households, labour market and prices by area.
None · JSON
10k+/day
no machine-readable spec
Open Government, MexicoFreeUntested
Mexico's national statistics API: economic, demographic and geographic indicators by state and municipality.
API key · JSON
Unlimited
no machine-readable spec
Open Government, SwedenFreeLive
Statistics Sweden's official statistical database API: population, economy, labour market and more.
None · JSON
—
no machine-readable spec
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Choosing a Census & Demographics API
Is there a free Census & Demographics API?
Yes. Census.gov, Data USA, GENESIS-Online, ONS API (Office for National Statistics), Open Government, Mexico and 1 other are free to use, and Genderize.io, Agify.io, NameGender and Nationalize.io have a free tier alongside paid plans.
Which Census & Demographics APIs work without an API key?
Data USA, IBGE, ONS API (Office for National Statistics) and Open Government, Sweden need no key or sign-up, so you can try them with a plain request.
Can I call a Census & Demographics API from front-end JavaScript?
Data USA, IBGE, ONS API (Office for National Statistics) and Open Government, Sweden allow cross-origin requests and need no key, so they work straight from the browser. For the others, call them from your server so your key stays private.
Can I use Census & Demographics APIs in a commercial project?
Census.gov, Genderize.io, Agify.io, ONS API (Office for National Statistics) and Open Government, Sweden permit commercial use. Data USA restricts it, for example to non-commercial or attributed use, so read the terms first.
Which Census & Demographics APIs work with AI agents?
NameGender publishes an OpenAPI spec for generating clients and tools.
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