Genderize.io

Free REST API that predicts the gender of a first name with probability scores based on name statistics from millions of users worldwide. Part of the Demografix suite alongside Agify (age prediction) and Nationalize (nationality prediction), sharing a single API key across all three services.

Genderize.io publishes 1 API on the APIs.io network: Gender Prediction API. Tagged areas include Gender, Name, Prediction, Demographics, and Machine-Learning.

The Genderize.io catalog on APIs.io includes 1 JSON-LD context and 1 Spectral governance ruleset.

Genderize.io’s developer surface includes documentation, pricing, FAQ, engineering blog, and 11 more developer resources.

🌐 Visit website 📡 Source on GitHub

41.3/100 developing ▬ flat Agent 33/100 agent ready saas Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0

AccessFreemium

1 APIs

GenderName Prediction Demographics Machine-Learning Statistics

Kin Score

Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0

Composite quality — 41.3/100 · developing

Contract Quality 14.3 / 25

Developer Ergonomics 1.9 / 20

Access Clarity 11.3 / 20

Operational Transparency 5.8 / 13

Contract Governance 1.2 / 12

Discoverability 6.9 / 10

Agent readiness — 33/100 · agent ready

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 0 / 12

Machine-Readable Auth 0 / 10

Idempotency 9 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 7 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 4 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Create-or-Update Ergonomics does not apply to this provider. The published contracts declare no write operations, and a read-only API cannot create-or-update. The facet is excluded from this provider's denominator entirely — not scored zero. A reference or data API is not deficient for being unable to upsert.

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/genderize: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 1

Individual APIs this provider publishes, each with its own machine-readable definition.

Genderize.io Gender Prediction API

Predict the gender of one or more first names.

Open Collections 2

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

API Collection

OPEN COLLECTION

Genderize.io Gender Prediction API

OPEN COLLECTION

Pricing Plans 1

Published pricing tiers and plan structures.

Genderize Plans Pricing

3 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Genderize Rate Limits

4 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Genderize Finops

FINOPS

Semantic Vocabularies 1

JSON-LD contexts and semantic vocabularies used across these APIs.

context Context

2 classes · 6 properties

JSON-LD

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs.

Genderize.io API Rules

4 rules · 3 warnings 1 info

SPECTRAL

JSON Schema 2

Standalone JSON Schema definitions for this provider's data models.

ErrorResponse

1 properties

JSON SCHEMA

GenderPrediction

4 properties

JSON SCHEMA

Examples 5

Example request and response payloads for these APIs.

Authenticated Request

3 fields

EXAMPLE

Batch Names Request

3 fields

EXAMPLE

Country Scoped Request

3 fields

EXAMPLE

Single Name Request

3 fields

EXAMPLE

Unknown Gender Response

3 fields

EXAMPLE

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Genderize Domain Security

TLSv1.2 · DNSSEC · DMARC

SECURITY

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Genderize Agentic Access

1 operation

1 operations · 0 acting

AGENTIC

Resources

Get Started 1

Portal, sign-up, and the first successful call

Login

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrg

GitHubOrg

Access & Security 1

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Operate 3

Status, limits, changes, and where to get help

RateLimits

RateLimits

FAQ

FAQ

StatusPage

StatusPage

Commercial 3

Pricing, plans, and the legal terms of use

Pricing

Pricing

Plans

Plans

FinOps

FinOps

Company 3

The organization behind the API

Website

Website

Blog

Blog

LinkedIn

Other 1

Properties that don't map to a standard resource type

Source (apis.yml)

aid: genderize
name: Genderize.io
description: Free REST API that predicts the gender of a first name with probability scores based on name statistics from
  millions of users worldwide. Part of the Demografix suite alongside Agify (age prediction) and Nationalize (nationality
  prediction), sharing a single API key across all three services.
deliveryModel:
  model: saas
  open_source: false
  commercial: true
  callable_host: true
  label: Hosted service · you call their endpoint
  confidence: high
  source:
  - openapi
  - pricing
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: freemium
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Freemium
  confidence: medium
  source:
  - plans
  generated: '2026-07-22'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/genderize.png
url: https://raw.githubusercontent.com/api-evangelist/genderize/refs/heads/main/apis.yml
created: '2026-06-13'
modified: '2026-06-13'
specificationVersion: '0.23'
tags:
- Gender
- Name
- Prediction
- Demographics
- Machine-Learning
- Statistics
tags_raw:
- Gender
- Names
- Prediction
- Demographics
- Machine Learning
- Statistics
apis:
- aid: genderize:genderize-gender-prediction-api
  name: Genderize.io Gender Prediction API
  description: Predict the gender of one or more first names.
  humanURL: https://genderize.io
  baseURL: https://api.genderize.io
  tags:
  - Gender Prediction
  properties:
  - type: OpenAPI
    url: openapi/genderize-gender-prediction-api-openapi.yml
  - type: Documentation
    url: https://genderize.io/documentation/api/reference
common:
- type: AgenticAccess
  url: agentic-access/genderize-agentic-access.yml
- type: DomainSecurity
  url: security/genderize-domain-security.yml
- type: Website
  url: https://genderize.io
- type: Documentation
  url: https://genderize.io/documentation
- type: Pricing
  url: https://genderize.io/pricing
- type: Plans
  url: plans/genderize-plans-pricing.yml
- type: RateLimits
  url: rate-limits/genderize-rate-limits.yml
- type: FinOps
  url: finops/genderize-finops.yml
- type: Login
  url: https://genderize.io/login
- type: FAQ
  url: https://genderize.io/faq
- type: Blog
  url: https://genderize.io/blog
- type: X
  url: https://x.com/genderizeio
- type: GitHubOrg
  url: https://github.com/genderize
- type: LinkedIn
  url: https://www.linkedin.com/company/demografix
- type: StatusPage
  url: https://status.genderize.io
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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