JSON Schema Validator
Validate JSON data against schema definitions
Input JSON
Output
What is JSON Schema Validator?
JSON Schema defines the structure, types, and constraints that valid JSON must satisfy. Our validator checks your JSON data against a schema definition, reporting all violations with clear paths to the offending values.
Schema validation catches type mismatches, missing required fields, invalid formats (like emails or dates), and constraint violations (min/max values, patterns) automatically.
Why Use This Tool?
Runtime type checking prevents bugs. When APIs receive user input, schema validation ensures data integrity before processing. When services exchange JSON, schemas serve as contracts that both parties can verify.
Documentation and validation become one: a well-written schema documents your data structure while simultaneously enforcing it. This single source of truth reduces inconsistencies between docs and implementation.
How It Works
Validation traverses the JSON against the schema:
• Type checks: string, number, boolean, array, object, null • Required fields: must be present • Enum: value must be in allowed list • Pattern: strings must match regex • Format: email, date-time, uri, etc. • MinLength/MaxLength, Minimum/Maximum • Custom keywords via schema extensions
Common Use Cases
- API request/response validation
- Configuration file verification
- Data quality assurance
- Form input validation
Pro Tip
Generate TypeScript types from JSON Schema using tools like json-schema-to-typescript for type-safe development.
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