Developer Tools
JSON Schema Generator
Generate a starter JSON Schema from example JSON locally in your browser for API contracts, validation, tests, and documentation.
JSON Schema Generator
Paste example JSON and generate a starter JSON Schema locally in your browser for API contracts, validation, tests, and documentation.
What this JSON Schema Generator is for
Use this JSON Schema Generator when you have an example API response, request body, fixture, config file, or mock payload and need a schema starting point.
It is useful for backend API documentation, contract discussions, validation setup, test fixtures, and quick checks before you write a stricter schema by hand.
How to use it
Paste valid JSON, choose a root title, pick a schema draft, and generate the schema.
Keep Require observed object fields enabled when every field in the sample should be considered required. For arrays of objects, the generator merges all items by default so fields missing from some items are treated more carefully.
Use Disallow additional object properties only when you want the generated object schemas to be strict. Leave it off when the example is incomplete or the real API may return extra fields.
Related tools
Use the JSON Formatter to validate or clean the input first, the JSON Pointer Resolver for exact RFC 6901 paths, the JSONPath Tester to inspect nested fields, the CSV to JSON Converter when starting from tabular data, and the JSON to TypeScript Types Generator when you also need TypeScript types from the same payload.
FAQ
JSON Schema Generator questions
Does this JSON Schema Generator upload my JSON?
No. JSON parsing and schema generation run locally in your browser, and the tool does not send your input to a server.
Can generated JSON Schema be used in production?
Use the generated schema as a first draft. Review required fields, optional fields, nullable values, formats, enums, and validation constraints before relying on it in production.
How are arrays handled?
By default, the generator merges all array items to infer a broader item schema. You can switch this off when you only want the first item sampled.
Which JSON Schema drafts are supported?
The first version can emit a Draft 2020-12 or Draft 7 schema URI. The inferred structure is intentionally lightweight and focuses on common object, array, primitive, and nullable values.