Validate your JSON document against a JSON schema to ensure it conforms to the expected structure and format.
Ctrl+Enter to validate | Ctrl+L to clear
The JSON Schema Validator verifies that JSON data conforms to a specified schema, ensuring data integrity, structure compliance, and type safety across applications and APIs. Essential for developers implementing data validation, API contract testing, or configuration verification, it supports multiple JSON Schema draft versions and provides detailed error reporting when validation fails. Whether you're enforcing API specifications, validating user input, or ensuring data consistency across services, the validator handles complex schemas with nested objects, arrays, and custom validation rules.
You can paste schemas and data directly, upload files, or work with schema libraries to validate your JSON against predefined structures. Because validation runs client-side, your data stays private and results appear instantly without server dependencies. The tool pairs naturally with the sample generator — create schemas, generate sample data, then validate it. Perfect for API testing, data pipeline validation, or ensuring configuration files meet specifications. Try validating data against different schema versions to see how constraint violations are reported.
All validation happens in your browser. No schemas or data are sent to our servers, ensuring complete privacy.
Instant validation with detailed error reporting and precise constraint checking.
Supports all JSON Schema features including complex validations, custom formats, and references.
Responsive design works perfectly on desktop, tablet, and mobile devices. No installation required.
JSON Schema Validator is a free online tool that validates JSON data against a JSON Schema definition. It checks if your JSON data conforms to the specified schema structure, data types, and validation rules. The validator provides real-time feedback with detailed error messages and line numbers indicating exactly where validation fails.
Our validator supports JSON Schema drafts 3, 4, 6, and 7. You can use schemas written in any of these draft versions. The tool automatically detects and validates against your specified schema format.
We support comprehensive format validation including email (RFC 5322), date (RFC 3339), time, date-time (ISO 8601), URI (RFC 3986), IPv4, IPv6, hostname, JSON Pointer, UUID (RFC 4122), and Base64 (RFC 4648) formats. These formats help ensure data type compliance beyond basic JSON structure validation.
Common use cases include API contract testing to ensure responses match schema definitions, configuration file validation, user input and form data validation, development testing with mock responses, data pipeline quality assurance in ETL processes, and compliance checking for structured data applications.
No — processing is performed client-side in the browser. We don't persist your data, send it to external servers, or track your validation activities. Your JSON data and schema remain completely private and are never stored.
File size limits depend on your device memory. Most modern devices can handle JSON files up to several megabytes. For very large files, consider chunking the data or using a server-based workflow.
Yes — the JSON Schema Validator is completely free to use with no signup required. All core validation features are available without any paywalls or usage limits.
When validation fails, the tool provides detailed error messages including the validation error type, the property that failed validation, and the line number where the error occurs. You can use this information to fix your JSON data to match your schema requirements.
Yes — the validator fully supports complex schema validation including arrays, nested objects, conditional schemas, and multiple data types. It validates the complete JSON structure against all schema constraints.
JSON Toolset stands out with its comprehensive validation features, support for multiple JSON Schema draft versions, detailed error reporting with line numbers, RFC-compliant format validators, and complete privacy with client-side processing. No sign-ups, no data storage – just efficient, secure JSON schema validation right in your browser.