JSON Schema Validator
Validate JSON data against a JSON Schema (Draft-07). Instant error reporting.
Supported keywords:
type, required, properties, items, enum, minLength, maxLength, pattern, minimum, maximum, multipleOf, minItems, maxItems, format (email, uri)
About JSON Schema Validator
Paste a JSON Schema (Draft-07) in the left panel and a JSON document in the right panel. The validator instantly reports all errors with the exact path and constraint that failed. Supports all Draft-07 keywords: type, required, properties, additionalProperties, minLength, maxLength, minimum, maximum, pattern, format, enum, oneOf, anyOf, allOf, and not. All validation runs in the browser.
All processing happens entirely in your browser using modern web APIs. Nothing is uploaded to our servers — your data stays local and private. Free to use forever, with a Pro plan for power users who want an ad-free experience and API access.
Common use cases
- Validating API request or response payloads against a JSON Schema spec
- Testing JSON Schema definitions during API development
- Checking configuration files against a schema before deploying
- Learning JSON Schema by seeing exactly which constraint fails
- Validating form data or user input structures against a defined schema
How it works
Uses the Ajv (Another JSON Validator) library running in the browser. Ajv compiles the schema into a validation function on first run, then executes it against the data. Errors include the path to the failing field (e.g., /user/email) and the constraint that was violated (e.g., "must match format \"email\""). Ajv is one of the fastest JSON Schema validators available.