JSON Schema Validator
FormatValidate JSON data against a JSON Schema locally and catch errors before shipping.
Validation Report
Run a validation to see results.
Everything runs locally in your browser. Supported keywords include type, properties, required, items, enum, min/max, pattern, and basic $ref pointers.
How it works
Paste a JSON Schema and JSON data, then validate. The tool checks structure, types, and constraints and returns a readable report. It runs entirely in the browser for privacy.
Supported checks
- Type validation for objects, arrays, strings, numbers, booleans, null, and integers
- Required properties, enums, const values, patterns, and length constraints
- Array items, min/max items, and uniqueItems
- Basic format checks for email, uri, and date-time
- Local $ref pointers like #/definitions/... or #/$defs/...
Common use cases
- Validating API payloads before sending requests
- Checking JSON exports from apps or spreadsheets
- Debugging schema rules during development
