The JSON Schema Generator creates a complete JSON Schema (draft-07) from any JSON data you provide. It automatically infers types, identifies required fields, and handles nested structures — giving you a production-ready schema in seconds instead of writing one by hand.
Step-by-Step
Paste your JSON — Enter any valid JSON object or array into the input panel.
Set a schema title — Optionally provide a title and description for the root schema.
Click Generate — The tool analyzes your JSON structure and produces a complete JSON Schema.
Review and customize — Inspect the generated schema, toggle required fields, and adjust types if needed.
Copy or download — Use the clipboard button or download the schema as a .json file for your project.
Features
Type Inference — Automatically detects string, number, integer, boolean, null, object, and array types from your JSON values.
Required Field Detection — All fields present in the sample are marked as required by default, with the option to toggle individual fields.
Nested Object Schemas — Deeply nested objects generate their own properties blocks with proper type: "object" wrappers.
Array Item Schemas — Arrays are analyzed to determine the item type. Mixed-type arrays generate oneOf schemas.
Draft-07 Compliance — The output follows the JSON Schema draft-07 specification, compatible with validators like Ajv, jsonschema, and JSON Schema Validator.
Format Hints — Common patterns like dates, emails, URIs, and UUIDs are detected and annotated with the appropriate format keyword.
Common Use Cases
API Validation — Generate schemas for request and response bodies to use with Express validators, Fastify schemas, or API Gateway request validation.
Form Generation — Use the schema with libraries like react-jsonschema-form or Formik to auto-generate forms from your data model.
Documentation — Include generated schemas in your API docs or OpenAPI/Swagger specifications for accurate, machine-readable type definitions.
Data Contracts — Establish schemas as data contracts between frontend and backend teams, ensuring both sides agree on the data structure.
Testing — Validate mock data and API responses against the generated schema in your CI/CD pipelines to catch type regressions early.
Why Use This Tool
Writing JSON Schemas by hand is tedious and error-prone, especially for complex nested structures with dozens of fields. This generator reverse-engineers the schema from real data, ensuring every field and type is captured accurately. It's perfect for bootstrapping validation, documentation, and form generation. Everything runs client-side in your browser, so sensitive data never leaves your device.
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