JSON to OpenAPI

Summary

Paste a sample JSON response and get a starter OpenAPI 3.0 components/schemas block with types and nested objects inferred.

How it works

1. Paste a sample JSON response into the input panel, or load an example.
2. Set a root schema name (defaults to RootObject).
3. Choose YAML or JSON output format.
4. Click Generate to parse the JSON and infer an OpenAPI 3.0 schema.
5. Nested objects become their own named schemas under components/schemas, referenced with $ref.
6. Copy the schema or download it as a file.

Use cases

• Bootstrap an OpenAPI spec from a real API response instead of writing schema by hand.
• Document a third-party API you consume but that has no published spec.
• Check which fields in a JSON payload are consistently present versus optional.
• Generate a starting schema for request or response validation.
• Speed up writing API documentation for an internal service.

Frequently Asked Questions