About the JSON Schema Validator
Validating API request bodies, configuration files, and database seeds against a defined contract is critical for preventing runtime errors. JSON Schema provides a standardized vocabulary to annotate and validate JSON documents. This JSON Schema Validator tests your JSON data against your schema and provides precise path-level validation error reports.
This tool is essential for backend API engineers building REST or GraphQL endpoints, QA automation testers verifying webhook payloads, and DevOps teams validating Kubernetes or OpenAPI schemas. It evaluates schema rules including data types ('string', 'number', 'boolean', 'array', 'object'), 'required' property constraints, 'enum' restrictions, 'minimum'/'maximum' numerical boundaries, 'minLength'/'maxLength', and regex 'pattern' rules.
To use it, paste your JSON data in the left panel and your JSON Schema in the right panel, then click 'Validate JSON Against Schema'. If validation passes, a green success confirmation appears. If errors exist, the tool displays an itemized list showing the exact JSON property path (e.g. '#/user/email') and why validation failed.
For example, if a schema requires 'age' to be an integer with a minimum value of 18, inputting 'age: 16' will immediately highlight '#/age: Value 16 is less than minimum 18'.
A common mistake in JSON Schema is defining regex patterns without escaping special characters properly in JSON strings.
Tip: Keep your schema definitions modular. You can validate nested objects and array item schemas recursively with this tool.