Generate JSON Schema from any JSON object instantly. Produces draft-07 compatible schemas with types, required fields and nested object definitions. Free online tool.
This JSON Schema generator takes any JSON object and produces a valid JSON Schema draft-07 definition, automatically inferring types, detecting required fields and handling nested objects and arrays recursively. The entire conversion runs in your browser - no data is ever sent to a server.
JSON Schema is a vocabulary for annotating and validating JSON documents. It defines the expected structure of a JSON object - which fields are required, what data type each field must be, minimum/maximum values, string pattern constraints, and more. JSON Schema is used to validate API request and response payloads, generate form UIs automatically, power TypeScript type checking with tools like AJV and Zod, document API contracts in OpenAPI/Swagger specifications, and validate configuration files in editors like VS Code.
Paste your JSON into the left panel above and the generator produces a JSON Schema draft-07 definition instantly. Toggle options to mark all fields as required, set additionalProperties: false to reject unknown fields, or allow null values. Click "Copy Schema" to copy the output for use in your project. The schema is generated live as you edit the JSON - syntax errors in the input are reported immediately below the input panel.
JSON Schema has several published draft versions. Draft-07 (2017) is the most widely supported - it introduced if/then/else conditional validation, readOnly/writeOnly keywords, and is the basis for many popular validators including AJV default configuration. Draft-2020-12 is the latest stable specification, adding improved $defs references and unevaluatedProperties, but has less tool support. This generator targets draft-07 as the safe default for maximum compatibility with validation libraries and OpenAPI 3.0 tooling.
The most popular JSON Schema validator for JavaScript and TypeScript is AJV (Another JSON Validator). Install it with npm install ajv, then: const ajv = new Ajv(); const validate = ajv.compile(schema); const valid = validate(data);. If valid is false, validate.errors contains detailed error messages. AJV is extremely fast and supports draft-07 fully. For TypeScript projects, pair AJV with ajv-ts to get TypeScript types inferred directly from your JSON Schema definition.
Completely. This JSON Schema generator runs entirely in your browser - your JSON data is never sent to any server, stored, or logged. The schema generation logic is pure JavaScript that runs locally on your device. It is safe to paste API responses containing sensitive user data, internal configuration, or proprietary business logic for schema generation. No network requests are made when you use this tool.