# facebook/prop-types

Runtime type checking for React props and similar objects

Repository: https://github.com/facebook/prop-types
Canonical: https://ross.abutalabs.com/products/prop-types
Language: JavaScript
License: MIT
License Family: permissive
Archived: true
Last push: 2024-05-17T08:15:01+00:00

## Health v2 (maintenance only)
Score: 10/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 3435, "days_push": 838, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, archived
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 4448, forks 347 (observed 2026-08-28T04:08:50.441094+00:00)

## What it is
A JavaScript library for runtime type checking of React component props and similar objects. It lets developers document expected property types and warns in development when passed props don't match the declared validators.

## Use cases
- validate react component props at runtime
- document expected types of component properties
- warn developers when props don't match definitions
- type check props in plain javascript objects
- add prop validation to legacy react class components

## When to choose
- you use React (or similar component libraries) and want lightweight runtime prop validation
- you need to document intended prop types for components without adopting TypeScript
- you want development-time warnings for incorrect props in a JavaScript codebase

## When to avoid
- your project already uses TypeScript or Flow for static type checking
- you need runtime validation of arbitrary data structures rather than component props
- you want a modern actively developed validation solution

## Facets
- artifact type: library
- maturity: maintenance
- function: type-system, frontend-framework, developer-tools
- domain: web-development, frontend, developer-tools
- platform: browser
- tags: react, prop-validation, runtime-type-checking, npm-package, development-warnings, nodejs, javascript

## Member repositories
- facebook/prop-types (main) score 10

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:08:50.441094+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T18:20:47.347108+00:00, confidence not recorded.
  - readme: https://github.com/facebook/prop-types (fetched 2026-08-28T04:08:50.441094+00:00, sha 3f17d7059015)
  - registry_npm: https://registry.npmjs.org/prop-types (fetched 2026-08-29T09:08:11.159017+00:00, sha bbbb744ae19c)
- Data as of 2026-08-30T08:39:29.467469+00:00.