JSON Schema Validator
JSON Schema is a powerful standard for describing the structure of JSON data. While basic JSON validators only check for missing commas or brackets, a Schema Validator ensures your data actually conforms to business rules (e.g., 'age must be an integer > 18' or 'email must be formatted correctly'). Our tool uses the industry-standard AJV engine to provide lightning-fast, secure, offline validation directly in your browser.
100% Private & Secure
This tool runs completely inside your browser using client-side WebAssembly and JS. Zero data is ever sent to our servers.
How to use this tool
- Paste your JSON Schema definition into the left editor.
- Paste the target JSON payload into the right editor.
- The validation engine runs automatically and instantly as you type.
- If the JSON is invalid, expanding error paths (like `/users/0/email`) will highlight exactly what rule was broken.
- Use the 'Test Invalid' and 'Test Valid' buttons to see how the validation engine catches constraint violations.
Example Usage
{
"type": "object",
"required": ["id"]
}// If payload is { "name": "Bob" }
Validation Failed
root must have required property 'id'{
"properties": {
"email": { "format": "email" }
}
}// If payload is { "email": "not-an-email" }
Validation Failed
/email must match format "email"When to use this tool
- Backend engineers writing draft-07 schemas for API documentation (OpenAPI/Swagger).
- Frontend developers mocking Formik or React Hook Form validation logic against a schema.
- Debugging complex CI/CD pipeline failures caused by invalid configuration file structures.
- Testing format constraints (`uuid`, `ipv4`, `date-time`) without writing custom regex.
Frequently Asked Questions
Which JSON Schema drafts are supported?
Our validator is powered by AJV, which fully supports draft-07 (the most widely used industry standard) as well as draft-2019-09 and draft-2020-12.
Does it validate specific formats like emails or IPs?
Yes. By default, we include standard format validation so constraints like `{"format": "email"}`, `uuid`, `uri`, and `date-time` are strictly enforced.
Is my proprietary API schema secure?
Absolutely. The AJV validation engine runs 100% locally in your browser leveraging WebAssembly or client-side JS. We never transmit your schemas or payloads to an external server.
What is the difference between this and the 'JSON Validator' tool?
The standard JSON Validator only checks syntax (brackets, quotes). This JSON Schema Validator enforces structural constraints (types, required fields, max lengths) defined by a separate schema.