What is a JSON Schema Validator?
A JSON Schema Validator compares a JSON instance with a schema that defines allowed types, required properties, value constraints, array rules, and object structure.
JSON Tools
JSON Schema validation guideJSON Schema Validator
Validate JSON data against JSON Schema and review clear, developer-friendly validation errors.
Paste JSON data and a JSON Schema to begin.
JSON data
The instance to validate against the schema.
JSON Schema
Draft 7, 2019-09, and 2020-12 are detected from $schema.
Validation report
Syntax, schema compilation, validation status, and actionable errors.
Ready to validate against JSON Schema
Paste JSON data and a schema, or load a sample. Validation runs only in this browser session.
JSON Schema Validation Guide
Check whether JSON data satisfies an explicit contract
Validate API payloads, configuration objects, test fixtures, and generated JSON against structural and value rules before they reach another system.
JSON syntax vs JSON Schema validation
Syntax validation asks whether JSON can be parsed. Schema validation first requires valid JSON, then checks whether the parsed value follows a separate contract.
How to use this tool
Paste JSON data, paste a JSON Schema, choose Validate against schema, then review the status, summary cards, instance paths, schema paths, keywords, and details.
Common validation errors
Frequent failures include missing required properties, incorrect types, enum or const mismatches, values outside minimum or maximum bounds, string length or pattern failures, and unexpected properties.
Supported features
The validator supports common JSON Schema keywords including type, required, properties, items, enum, const, numeric limits, string limits, patterns, and additionalProperties.
Limitations
Draft 7, 2019-09, and 2020-12 are selected from $schema. Schemas without it use Draft 7 behavior. Format extensions are not enabled, and remote references are never fetched.
Privacy
JSON parsing, schema compilation, and validation run locally. Source data, schemas, validation paths, errors, and reports are not sent through analytics or uploaded.
JSON Schema Validator FAQ
Does this tool upload JSON data or schemas?
No. Validation runs locally in your browser.
What is the difference between JSON Validator and JSON Schema Validator?
JSON Validator checks syntax only. JSON Schema Validator checks valid JSON data against rules in a separate schema.
Which JSON Schema drafts are supported?
Draft 7, Draft 2019-09, and Draft 2020-12 are supported. The tool detects a recognized $schema URI when present.
Can this validator fetch remote $ref schemas?
No. Remote loading is disabled to keep processing local and predictable. Include referenced schemas locally.
Will validation change my JSON?
No. Type coercion, defaults, and automatic property removal are disabled.
Why did schema compilation fail?
The schema may contain invalid keyword values, use an unsupported draft, reference a missing schema, or include a keyword that strict compilation does not recognize.
What does instance path mean?
The instance path identifies the location in your JSON data that failed validation. The schema path identifies the rule that produced the error.
Are format values such as email validated?
No. This version does not expose optional format validation, so format is treated as annotation rather than an enabled format check.