JSON Schema Generator
Paste a JSON sample and get a valid JSON Schema instantly. Supports Draft-07 and 2020-12.
Automatically detects string formats (date-time, email, uri, uuid, date),
distinguishes integer from number, and handles nested objects and arrays.
Everything runs in your browser.
Supported formats: date, date-time, email, uri, uuid • Distinguishes integer vs number • All fields marked as required • Runs 100% in your browser.
Frequently Asked Questions
What is JSON Schema and why do I need it?▼
JSON Schema is a standard for describing the structure and validation rules of JSON data. It defines required fields, data types, string formats, and value constraints. Use it for API request/response validation, form validation, configuration file checks, and code generation.
What is the difference between Draft-07 and 2020-12?▼
Draft-07 is the most widely supported version — compatible with most validators and tools. 2020-12 is the latest standard with new features like $dynamicRef, prefixItems for tuples, and improved vocabulary support. Use Draft-07 for maximum compatibility; use 2020-12 for new projects.
What string formats does the tool detect?▼
The tool automatically detects date-time (ISO 8601), date, email, uri, uuid, and IPv4/IPv6 formats from your sample data. Format annotations help validators enforce stricter checks beyond just 'string' type.
How does it handle arrays with different element types?▼
If all array elements share the same structure, the tool generates a single items schema. If elements are mixed types, it generates a oneOf or anyOf union schema. Empty arrays default to an open items schema.
Can I use the generated schema with AJV or Zod?▼
Yes. The generated JSON Schema works with AJV (the fastest JSON Schema validator for JavaScript), Python's jsonschema library, and can be converted to Zod schemas using tools like json-schema-to-zod. It follows the official JSON Schema specification.
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