Private, ad-free JSON workspace
Paste or import JSON to infer a reusable contract, then generate JSON Schema, TypeScript, Zod, Go, Rust, Java, Kotlin, Pydantic, or OpenAPI schema output. It is built for developers turning API responses, webhook payloads, config files, and fixtures into safer code.
{
"id": 42,
"name": "Ada",
"roles": ["admin", "editor"],
"active": true
}interface Root {
id: number;
name: string;
roles: string[];
active: boolean;
}A sample object on the left, inferred TypeScript types on the right.
The generator looks at the JSON you paste and infers a shape from it: field names, value types, arrays, and nested objects. Because it works from a sample, the quality of the output depends on the sample. If a field is sometimes null or sometimes missing, include an example that shows that so the inferred type reflects reality rather than one lucky payload.
The base output is a JSON Schema draft 2020-12 contract. Everything else, the TypeScript interfaces, Zod schemas, Go and Rust structs, and the rest, is generated from that same inferred shape, so they agree with each other.
The point of generating types is to stop hand-writing them. Paste a new API response, get an interface or a struct, and wire it straight into your client. For untrusted input, generate a Zod schema and validate at the boundary so bad data fails fast instead of leaking into your app.
Schema and type generation run in your browser, so source JSON is not uploaded to JSON Toolbox servers.
Yes. The schema tool infers a JSON Schema draft 2020-12 contract from valid JSON in the browser.
Yes. The schema workspace can generate TypeScript types, Zod validator code, Go structs, Rust serde structs, Java POJOs, Kotlin data classes, and Pydantic models from the inferred JSON Schema.
Inference only sees the sample you paste. If a field is missing or null in some payloads, include an example that shows that so the output marks it optional or nullable.
It infers a JSON Schema draft 2020-12 contract, and the other type outputs are generated from that same shape.
Yes. JSON parsing, schema inference, and type generation run locally in your browser.