JSON Schema Generator

About this tool

Paste a sample JSON object or array and get a matching JSON Schema (draft-07) — including nested objects, arrays, and required-field detection from arrays of objects with inconsistent keys.

Types are inferred from a single sample — if a field is sometimes a different type in other real data, double-check the generated schema. Everything runs locally in your browser.

Frequently asked questions

How does it decide which fields are "required"?

For a plain object, every key present is marked required. For an array of objects, a key only becomes required if it appears in every element of your sample array — keys missing from at least one element are left out of required.

What's the difference between "integer" and "number" in the output?

JSON Schema distinguishes whole numbers (integer) from numbers with a decimal component (number) — this tool checks your sample value itself, so 5 becomes integer but 5.0 parsed from JSON also becomes integer (JSON doesn't distinguish them at the syntax level either).

Is my JSON uploaded anywhere?

No — parsing and schema generation both happen entirely in your browser.