Validate your JSON data against a JSON Schema directly in your browser. This tool checks type constraints, required fields, string patterns, numeric ranges, enums, array items, and more. No data is sent to any server — everything runs client-side. Perfect for API development, configuration validation, and data quality checks.
JSON Schema defines the structure, data types, and constraints that valid JSON data must follow — like a contract for your API. It specifies which properties are required, what types they should be (string, number, boolean), value constraints (minimum, maximum, pattern), and nested structure. This validator checks your JSON data against a schema and reports all violations with clear descriptions and property paths. Essential for API development (validating request/response bodies), configuration management (ensuring config files are correct), data pipeline testing (verifying data quality), and documentation (schemas serve as machine-readable API docs).
A vocabulary for annotating and validating JSON documents. It defines expected structure, types, and constraints. Written in JSON itself, it describes what valid data looks like: required fields, allowed values, nested structures.
Draft 2020-12 is the latest standard. Draft-07 is the most widely supported across tools and libraries. Use the version your ecosystem supports — most validators handle multiple drafts.
Yes — several tools infer schemas from sample data. However, generated schemas are starting points, not production-ready. They can't know business rules, optional fields, or value constraints from examples alone.
Properties listed in the 'required' array must be present. All other properties are optional by default. Use 'additionalProperties: false' to disallow any properties not defined in the schema.
Use nested 'properties' definitions or '$ref' to reference sub-schemas. For arrays of objects, use 'items' with a schema. JSON Schema fully supports arbitrarily deep nesting.