JSON Schema Generator
Generate JSON Schema from sample JSON data automatically. Create validation schemas, API documentation, and type definitions from your JSON examples with support for nested objects and arrays.
Schema Options
Recommended Settings
Schema Generation Tips
- •Provide comprehensive sample data with all fields you want in the schema
- •Include multiple array items to ensure accurate schema generation
- •Use representative values that show the expected data types
Schema Customization
- •Enable 'Include examples' for documentation and testing purposes
- •Use 'Mark all required' as a starting point, then customize as needed
- •Generated schemas use JSON Schema Draft 7 specification
Pro Tips
- •Paste sample JSON - the tool auto-generates schema when valid JSON is detected
- •Review generated schema and adjust required fields based on your needs
- •Use the schema for API validation, documentation, or code generation
- •Download the schema to use with JSON Schema validators
Most Popular
Most users include examples for documentation and manually adjust required fields
When to Use This Tool
Generate JSON Schema for API request and response documentation. Schema provides clear, machine-readable specifications of your API data structures that can be used for automatic documentation generation and client SDK creation.
Create validation schemas to ensure incoming data matches expected structure and types. Use the generated schema with JSON Schema validators to automatically validate data in your applications and catch errors early.
Generate JSON Schema as a basis for creating TypeScript interfaces, Go structs, or other strongly-typed definitions. Many code generators accept JSON Schema as input to generate type-safe code.
Use generated schemas with example values to create mock data generators for testing. The schema with examples can automatically generate realistic test data that matches your production data structure.
How It Works
Paste your sample JSON data into the input field - use real data with all fields you want to document
Optionally enable 'Include example values' to add actual data as examples in the schema
Enable 'Mark all required' if you want all fields marked as required by default (you can adjust later)
Click 'Generate Schema' or simply paste - the tool auto-detects valid JSON and generates the schema
Review the generated JSON Schema Draft 7 specification with type information and structure
Copy to clipboard for immediate use or download as schema.json for your project
All processing happens in your browser - your JSON data never leaves your device
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Files never leave your device. All processing happens locally in your browser.
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Frequently Asked Questions
What is JSON Schema?
JSON Schema is a vocabulary that allows you to annotate and validate JSON documents. It describes the structure, data types, and constraints of your JSON data. Think of it as a blueprint that defines what valid JSON should look like.
How accurate is the generated schema?
The schema is generated based on your sample data. It infers types and structure from what you provide. For best results, include comprehensive sample data with all possible fields and representative values. Arrays should include at least one item to determine the item schema.
What does 'Mark all required' do?
This option marks every field in your JSON as required in the schema. By default, JSON Schema treats all fields as optional. Enable this as a starting point, then manually edit the schema to mark only truly required fields based on your needs.
Should I include example values?
Including examples is helpful for documentation and testing. Examples in your schema help developers understand expected values and can be used by mock data generators for testing. However, it increases schema file size, so disable if size is a concern.
Can I use the generated schema for validation?
Yes! The generated JSON Schema Draft 7 specification can be used with any JSON Schema validator library (like ajv for JavaScript, jsonschema for Python, etc.) to validate data. The schema defines types, structure, and required fields for validation.
How do I handle complex nested structures?
The generator automatically handles nested objects and arrays. Provide sample data with the full nested structure you need, and the schema will recursively describe each level. Arrays will use the first item to determine the schema for all items.