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JSON Schema Validator

Validate JSON data against a JSON Schema (Draft 07) with detailed error reporting. Generate schemas from sample data or load examples to get started.

Load example:
JSON Schema Quick Reference

JSON Schema is a vocabulary for annotating and validating JSON documents. It describes the structure, constraints, and documentation of JSON data.

Common keywords:
  • type — Data type: string, number, integer, boolean, object, array, null
  • required — Array of required property names
  • properties — Object property schemas
  • items — Schema for array elements
  • enum — Allowed values
  • pattern — Regex pattern for strings
  • minimum / maximum — Number range constraints
  • minLength / maxLength — String length constraints
  • format — Semantic format: email, uri, date-time, ipv4, uuid, etc.
  • additionalProperties — Allow or deny extra properties on objects
Combining schemas:
  • allOf — Must match all schemas
  • anyOf — Must match at least one schema
  • oneOf — Must match exactly one schema
  • not — Must not match the schema

This tool supports JSON Schema Draft 07 with format validation (email, URI, date-time, etc.) via ajv-formats. Everything runs in your browser — no data is sent over the network.