sindresorhus/type-fest

Health v2 · maintenance only

Adoption not part of the score

17381 stars · 731 forks observed · 2026-08-28

What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-29, confidence not recorded

A collection of essential TypeScript utility types that many feel should be built into the language. It is an npm package of type-only definitions that can be installed as a dependency or copy-pasted freely.

Use cases

• make specific object properties optional in TypeScript
• exclude keys from a TypeScript type
• get the type of array elements in TypeScript
• define deeply readonly object types
• write stricter JSON-typed values in TypeScript
• find commonly needed utility types missing from TypeScript

When to choose

• you write TypeScript and frequently need utility types like Partial, Except, or JsonObject
• you want a well-maintained, dependency-free set of type helpers
• you prefer copy-pasting types with no attribution required

When to avoid

• your project uses TypeScript older than 5.9 or is not strict-mode
• you need runtime validation or runtime helper functions rather than types
• you work in plain JavaScript without type checking

Facets

library · maturity active

type-system developer-tools developer-tools programming-languages cross-platform typescript utility-types npm-package type-definitions nodejs

Member repositories

For agents

markdown · JSON · MCP: product_card(name="sindresorhus/type-fest")