Development — entry 026 of 98
Genderize.io
Genderize.io, from the same Demografix ApS team behind Agify and Nationalize, predicts the likely gender for a first name from a worldwide dataset and returns a probability score plus the sample count behind it, with support for `country_id` filtering and batching up to 10 names per request. No key is needed for the free tier's 2,500 names a month; paid plans scale to 25 million requests a month.
Genderize.io predicts the likely gender for a first name, using a worldwide name dataset. It returns a probability score and the sample count behind the prediction. You can filter by country_id and batch up to 100 names in one request. Keyless calls work for a quick test. For the free tier of 2,500 names a month, register for a free API key.
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<a href="https://greatapis.com/api/genderize-io/"><img src="https://greatapis.com/badge/genderize-io.svg" alt="Scored 85 on greatapis.com"></a>Auth quickstart
- No API key required for a quick test. Keyless requests are public.
- For more than a few calls, register at genderize.io for a free key. The same key works on Genderize, Agify, and Nationalize.
Your key is stored only in this browser (localStorage) and sent directly to the API — never to greatapis.
Predict gender from a first name
GEThttps://api.genderize.io?name=peter
{"count":1352696,"name":"peter","gender":"male","probability":1.0}Developer reference
25 requests per rate-limit window per IP, unauthenticated (live X-Rate-Limit-Reset header showed ~27,900s to reset) -- the documented 2,500 names/month free-tier cap is separate from this enforced per-window ceiling.
Gotchas & limits
- Batch lookups use repeated
name[]params (e.g.?name[]=peter&name[]=lois&name[]=stewie), up to 100 names per request, and return a JSON array instead of a single object; each name in the batch counts against the monthly quota separately - Keyless calls carry
x-rate-limit-limit: 25with a multi-hour reset, per a live response header. The documented free tier of 2,500 names a month needs a free account key - Unrecognized or very rare names still return HTTP 200, with
genderset tonullrather than an error