What JSON Schema features are supported?

Objects with properties and required, arrays with items, string enums, number, boolean, null, $ref into definitions/$defs, and anyOf/oneOf rendered as union types. Unknown constructs fall back to unknown.

How are optional fields handled?

A property not listed in the schema's required array becomes optional with a trailing question mark, matching idiomatic TypeScript.

Why would I use this for LLM work?

Function-calling and structured-output schemas are JSON Schema. Generating matching TypeScript interfaces lets you parse tool-call arguments and model responses with full type safety.

Is my schema sent anywhere?

No. Code generation runs entirely in your browser. Nothing is uploaded or stored.

JSON Schema → TypeScript Types

Generate TypeScript types from JSON Schema

The JSON Schema → TypeScript converter turns a JSON Schema object into clean, idiomatic TypeScript interface definitions. It is built for the LLM era, where function-calling tool schemas and structured-output formats are expressed in JSON Schema — generating matching interfaces lets you parse tool arguments and model responses with full type safety.

How it works

The generator walks the schema recursively. Object types become interfaces; properties not in the required array become optional (?). Arrays map to T[], string enums map to string-literal unions, and $ref pointers resolve against definitions or $defs. anyOf and oneOf render as union types. Nested anonymous objects get auto-named child interfaces so the output stays readable. Unknown or unsupported constructs degrade gracefully to unknown.

Tips and notes

If your schema uses $ref, keep the referenced definitions under $defs or definitions so they resolve. For LLM tool calling, generate the interface for your function’s parameters schema and type the arguments you receive from the model. When a field can be several shapes, oneOf produces a discriminated-union candidate you can refine. The output is plain text — copy it directly into your project.