JSON Schema Generator

A JSON Schema generator takes sample JSON data and produces a JSON Schema that describes its structure. Instead of writing schema by hand, you paste example data and the tool infers types, nested objects, array item schemas, and optional format hints (email, uri, date-time, uuid). The result can be used for validation, documentation, or API specifications.

This tool supports draft-04, draft-06, and draft-07. It detects string formats via common patterns, suggests enums when arrays contain uniform primitive values, and lets you choose whether to mark all fields as required or optional. Add empty description placeholders to fill in later.

JSON Schema supports types: string, number, integer, boolean, null, array, object. The format keyword adds semantic hints: email (RFC 5322), uri, date, date-time (ISO 8601), uuid. Formats are not enforced by the core spec but many validators implement them. The generator detects these from your data: strings matching email pattern get format email, ISO dates get date-time, UUIDs get format uuid.

For arrays, the items schema describes each element. For objects, properties lists each key and its schema. Use required to list keys that must be present. The generator can mark all keys as required (strict) or leave them optional (flexible).

Copy the generated schema and paste it into your project. Use it with Ajv, tv4, or other validators in JavaScript; jsonschema in Python; or similar libraries in other languages. OpenAPI 3.x uses a subset of JSON Schema for request/response schemas. You can also use the schema for documentation (e.g., generating forms or API docs) or for runtime validation of API payloads. Refine the schema as needed: add minLength, maxLength, pattern, or custom keywords supported by your validator.