JSON Schema Validator
Paste a JSON Schema and JSON data side by side. See instant validation results with detailed error messages and property paths.
Valid
The JSON data satisfies all schema constraints.
Frequently Asked Questions
Which JSON Schema draft does this validator support?
The validator implements the most commonly used JSON Schema Draft-07 keywords: type, required, properties, additionalProperties, minLength, maxLength, minimum, maximum, exclusiveMinimum, exclusiveMaximum, multipleOf, enum, const, pattern, format (email, uri, date, date-time, uuid, ipv4), items, minItems, maxItems, uniqueItems, minProperties, maxProperties, not, allOf, anyOf, oneOf, and basic $ref resolution for local definitions.
What does the 'required' keyword do in a JSON Schema?
The 'required' keyword is an array of property names that must be present in a JSON object. If any listed property is absent from the data, the validator reports an error at the missing property's path. For example: { "required": ["name", "email"] } means both name and email must exist in the object.
How do I use anyOf, allOf, and oneOf?
allOf requires the data to be valid against every subschema in the array. anyOf requires the data to be valid against at least one. oneOf requires the data to be valid against exactly one subschema. These are useful for representing union types, conditional structures, and polymorphism in JSON schemas.
What formats are supported?
The format keyword validates: email (basic RFC pattern), uri/url (parsed with the URL constructor), date (YYYY-MM-DD), date-time (parseable by Date), uuid (8-4-4-4-12 hex), and ipv4. Unknown format values are silently accepted to avoid breaking schemas that use custom formats.
Is my schema and data sent to a server?
No. All validation logic runs entirely in your browser using JavaScript. Your schema definitions and JSON data never leave your device, making it safe for use with proprietary API contracts and internal data models.