JSON Schema Validator - Validate JSON Data Structure
Validate your JSON data against JSON Schema to ensure it meets required structure, types, and formats. Use built-in schema patterns for emails, URLs, dates, and more, or create custom schemas. Generate TypeScript types and schemas automatically from your JSON data.
JSON Data
JSON Schema
Validation Results
Powerful JSON Schema Validation Features
Everything you need to validate JSON structure, types, and formats with precision.
Schema Validation
Validate your JSON data against JSON Schema (Draft 4, 6, 7, 2019-09, 2020-12). Instantly see if your data meets required structure, types, and constraints.
Built-in Schema Patterns
Access a library of ready-to-use schema patterns including email addresses, URLs, dates, phone numbers, and more. No need to write schemas from scratch.
Generate Schema from JSON
Automatically generate JSON Schema from your existing JSON data. Perfect for creating validation rules quickly or documenting your data structure.
TypeScript Type Generation
Convert your JSON Schema into TypeScript interfaces and types automatically. Save time writing type definitions and ensure type safety in your projects.
Detailed Error Messages
Get clear, actionable validation errors with exact paths to problematic data. Know exactly what's wrong and where, making debugging quick and easy.
Multiple Schema Draft Versions
Switch between different JSON Schema specification versions (Draft 4, 6, 7, 2019-09, 2020-12) to ensure compatibility with your validation requirements.
How to Validate JSON with Schema
Validate your JSON data in three simple steps using our schema validator.
Add Your JSON Data
Paste your JSON data into the top editor or upload a JSON file. Your data appears ready for validation.
Add Your Schema
Click "Generate Schema" to auto-create from your JSON, then click "Use Schema" to add it to the editor.
View Results Automatically
Validation happens automatically in real-time. View results in the Validation tab—any errors show with exact paths and descriptions. Generate TypeScript types when valid.
Frequently Asked Questions
What is JSON Schema validation?
JSON Schema validation checks if your JSON data conforms to a defined schema—a set of rules about structure, data types, required fields, and formats. It ensures your data meets specifications before processing, preventing errors and data issues.
Which JSON Schema versions are supported?
Our validator supports JSON Schema Draft 4, Draft 6, Draft 7, Draft 2019-09, and Draft 2020-12. You can specify the schema version using the $schema property, or the validator will detect it automatically.
Can I generate a schema from existing JSON?
Yes! Click the "Generate Schema" button after pasting your JSON data. The tool analyzes your data structure and automatically creates a JSON Schema with inferred types, required fields, and patterns. You can then customize the generated schema.
What is TypeScript type generation?
Click the "TypeScript" button to automatically convert your JSON Schema into TypeScript interfaces and type definitions. This saves time writing types manually and ensures your types match your data structure perfectly.
What validation errors will I see?
Validation errors show the exact path to problematic data, the expected type or format, and what was found instead. For example: "data.email should match format 'email'" or "data.age should be number". This makes fixing issues quick and straightforward.
Is my JSON data stored or shared?
No. All validation happens locally in your browser using JavaScript. Your JSON data and schemas never leave your device. Everything stays private and secure on your computer.