JSON Schema to TypeScript

Convert a JSON Schema (draft-07) into TypeScript interfaces and type aliases — properties, required, enums, unions, $refs and nested objects included. Runs entirely in your browser.

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How it works

• Supports type, properties + required, additionalProperties, items (single schema or tuple array), enum → union literals, and anyOf/oneOf → unions.
• Local $refs into #/$defs or #/definitions are resolved — referenced definitions become named interfaces/aliases too.
• "null" in the type list or x-nullable: true produces T | null.
• Strict mode keeps required properties as non-optional (: T); otherwise every property becomes ?: T.
• format and pattern are ignored — they don’t affect the emitted type.

About JSON Schema to TypeScript

API contracts, config files and data fixtures are increasingly described with JSON Schema — but consuming that schema in TypeScript usually means either hand-writing the interfaces or pulling in a heavy build-time plugin. This tool does the translation in one pass: object schemas become interfaces, everything else collapses to primitive or union types, and local $defs/definitions are emitted as their own named declarations so the output stays readable.

The generated code is plain TypeScript — no dependencies, no generics machinery — so you can paste it into a .d.ts file or an existing source file and start using it immediately. The strict-mode toggle matches the two common conventions (all-optional by default vs. required-only-non-optional), and the prefix control avoids name collisions when you generate types for several schemas into the same file.