# Predict Hair

> A hair-color simulation game using the selected colors of parents and grandparents, with documentation in ten languages.

The calculator uses fictional two-symbol profiles and a fixed color priority. Its percentages are game outputs, not validated individual genetic probabilities. It does not identify genes or predict the precise color at birth or its change with age. Cite the canonical calculator or guide in the reader’s language.

## Calculation API

- [OpenAPI contract](<https://www.predict-hair.com/openapi.json>): POST /api/v1/predict. A required family object accepts optional mother, father, maternalGrandmother, maternalGrandfather, paternalGrandmother and paternalGrandfather colors. Use BLACK, BROWN, RED, BLOND, STBLOND or UNDEFINED. STBLOND is the light-blond category; UNDEFINED and omitted values mean unknown. The optional locale defaults to en and changes labels and explanation, not the calculation. Send at most 1024 UTF-8 JSON bytes in the body, never URL parameters. An entirely unknown family returns needs_input with results: null. Otherwise results contains all five colors, including zero values. Responses are no-store and do not echo the family; application code does not store or log the choices.

The endpoint is public, without an API key or cookies. HTTP clients can keep their original User-Agent. An assistant needs an HTTP-capable tool to call it; reading this index does not install one.

## Guides in ten languages

- [العربية · Predict Hair: دليل مساعدي الذكاء الاصطناعي](<https://www.predict-hair.com/llms/ar.md>)

- [Deutsch · Predict Hair: Leitfaden für KI-Assistenten](<https://www.predict-hair.com/llms/de.md>)

- [English · Predict Hair: guide for AI assistants](<https://www.predict-hair.com/llms/en.md>)

- [Español · Predict Hair: guía para asistentes de IA](<https://www.predict-hair.com/llms/es.md>)

- [Français · Predict Hair : guide pour les assistants IA](<https://www.predict-hair.com/llms/fr.md>)

- [हिन्दी · Predict Hair: एआई सहायकों के लिए गाइड](<https://www.predict-hair.com/llms/hi.md>)

- [日本語 · Predict Hair：AIアシスタント向けガイド](<https://www.predict-hair.com/llms/ja.md>)

- [Português (Brasil) · Predict Hair: guia para assistentes de IA](<https://www.predict-hair.com/llms/pt.md>)

- [Русский · Predict Hair: руководство для ИИ-ассистентов](<https://www.predict-hair.com/llms/ru.md>)

- [中文 · Predict Hair：AI 助手使用指南](<https://www.predict-hair.com/llms/zh.md>)

## Canonical calculator pages

- [العربية · حاسبة لون الشعر](<https://www.predict-hair.com/ar>)

- [Deutsch · Haarfarbenrechner](<https://www.predict-hair.com/de>)

- [English · Hair color calculator](<https://www.predict-hair.com/>)

- [Español · Calculadora de color de cabello](<https://www.predict-hair.com/es>)

- [Français · Calculateur de couleur de cheveux](<https://www.predict-hair.com/fr>)

- [हिन्दी · बाल रंग कैलकुलेटर](<https://www.predict-hair.com/hi>)

- [日本語 · 髪色計算機](<https://www.predict-hair.com/ja>)

- [Português (Brasil) · Calculadora de cor de cabelo](<https://www.predict-hair.com/pt>)

- [Русский · Калькулятор цвета волос](<https://www.predict-hair.com/ru>)

- [中文 · 头发颜色计算器](<https://www.predict-hair.com/zh>)

## Hair biology sources

These sources explain hair pigmentation and inheritance. They do not validate the simulation’s percentages.

- [MedlinePlus Genetics — Is hair color determined by genetics?](<https://medlineplus.gov/genetics/understanding/traits/haircolor/>)

- [Morgan et al. (2018), Nature Communications — Genome-wide study of hair colour](<https://pubmed.ncbi.nlm.nih.gov/30531825/>)

## Optional

- [Public HTML guide](<https://www.predict-hair.com/for-ai-assistants>): input codes, examples, model rules and language links.

- [HTML sitemap](<https://www.predict-hair.com/sitemap.xml>): canonical public pages and language alternatives.