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, Predictions, 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

38.1/100 thin ▬ flat Agent 43/100 agent native Front door AI 5/6 prominent saas Full breakdown ↓
scored 2026-09-25 · rubric v0.23.0

AccessFreemium

1 APIs

GenderName Predictions Demographics Machine Learning Statistics

Kin Score

Kin Score How this is scored →
scored 2026-09-25 · rubric v0.23.0

Composite quality — 38.1/100 · thin

Contract Quality 11.0 / 21

Developer Ergonomics 1.6 / 17

Access Clarity 9.1 / 17

Operational Transparency 4.6 / 11

Contract Governance 1.0 / 10

Discoverability 5.8 / 9

Regulatory Posture 1.5 / 15

Agent readiness — 43/100 · agent native

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 6 / 6

MCP Server 12 / 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

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

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.

The six quality facets above are damped to 85 points between them, because the conditional facet above carries the other 15. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 85% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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
- Predictions
- Demographics
- Machine Learning
- Statistics
tags_raw:
- Gender
- Names
- Prediction
- Demographics
- Machine Learning
- Statistics
- Machine-Learning
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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