Online JSON Schema generator: paste JSON data and automatically generate the corresponding JSON Schema definition. Supports nested objects, arrays, type inference, runs locally in browser.
TL;DR: Free online JSON Schema generator. Paste JSON and automatically generate the corresponding JSON Schema definition with nested object and array support and type inference. Runs locally in your browser, no registration.
This tool runs entirely in your browser. Open DevTools → Network panel and search your input — it appears in no request.
FAQ
Completely free, no registration required. Generate JSON Schema directly in your browser — all operations run locally with no usage limits.
It supports automatic inference of string, integer, number, boolean, null, object, and array types. Objects infer properties and required fields; arrays infer items type from the first element.
No. All JSON Schema generation runs locally in your browser. Your JSON data is never sent to any server.
The generated Schema follows JSON Schema Draft-07 specification, includes a $schema declaration at the top level, and can be used directly with validators like Ajv.
Arrays use the type of the first element as the items type. If the array is empty, only the array type is declared without items. For complex heterogeneous arrays, we recommend adjusting the Schema manually.
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