What is JSON Schema?
JSON Schema is a vocabulary for validating JSON documents. Define structure, types, and constraints for your data.
Why Use JSON Schema?
Ensure data integrity, document your API, automate validation, and catch errors early.
Basic Schema Structure
A schema defines the expected structure. Includes type definitions, required fields, and validation rules.
Data Types in JSON Schema
Supports string, number, integer, boolean, object, array, and null. Each type has specific validation keywords.
Validation Keywords
String Validation
minLength, maxLength, pattern (regex), format (email, uri, date-time).
Number Validation
minimum, maximum, multipleOf, exclusiveMinimum, exclusiveMaximum.
Array Validation
minItems, maxItems, uniqueItems, items (schema for array elements).
Required Fields
Use the "required" keyword to specify mandatory properties. Prevents missing data.
Advanced Features
$ref for schema reuse, definitions for shared schemas, allOf/anyOf/oneOf for complex validation.
Practical Examples
User profile schema, API request validation, configuration file validation.
Validation Tools
Use our JSON Schema Validator to test your schemas online instantly.
Best Practices
Keep schemas simple, document your schemas, use $schema version, provide examples.