JSON Schema Generator
Generate a JSON Schema (draft 2020-12) from sample JSON — types, nested objects, arrays, required fields and formats like email, date-time and URI.
How to use
- 1Paste a representative JSON sample — arrays with several items give better results.
- 2Copy the schema and refine descriptions, enums and limits by hand.
How it's calculated
Types are inferred from values; objects in an array are merged, and a field is 'required' only if it appears in every sample object.
Frequently asked questions
Which draft is generated?
JSON Schema draft 2020-12, which is supported by modern validators like Ajv and by OpenAPI 3.1.
Why is a field not required?
It was missing from at least one object in an array. Add it to all samples, or edit the 'required' list.
Can it detect enums?
No — a sample can't tell whether a value is one of a fixed set. Add enum lists manually.