JSON Schema Generator

Paste a JSON sample and get a draft JSON Schema (Draft 07) with inferred types and structure. Everything runs in your browser—nothing is uploaded.

Clear
Schema options

Output is a starting point only. One sample cannot prove optionality or union types—validate against real payloads before production.

Generated schema

HOW IT WORKS

How to generate JSON Schema from JSON

Paste a representative JSON document, adjust options, and copy or download a draft schema you can refine in your editor or validator.

Paste sample JSON

Use a realistic object or array that reflects the keys and value types you expect.

Tune required keys and extra properties

Decide whether every object key is required and whether unknown keys should be allowed.

Copy or download the schema

Export Draft 07 JSON Schema and refine it with tests and multiple samples.

WHY USE THIS TOOL

Why generate JSON Schema online?

Hand-writing schema for APIs and configs is slow. Inferring a first pass from sample JSON speeds up documentation and validation setup.

Fast first draft

Turn one JSON sample into typed object properties, arrays, and nested shapes.

Draft 07 compatible

Uses the widely supported JSON Schema Draft 07 meta-schema URI in the output.

Private in-browser

Your JSON never leaves the device; generation runs entirely in the page.

Sensible array handling

When array items differ, the tool can emit a compact oneOf of seen shapes.

PRIVACY

Private JSON Schema generation

Sample JSON and generated schema stay in your browser memory. Nothing is uploaded, logged, or stored on a server.

Data stays on device

Parsing and schema inference run locally in your browser tab.

No uploads or storage

We do not receive your JSON or schema; there is no account or cloud sync.

Runs in browser

Open the page and paste JSON—no install or backend required.

FAQ

Frequently asked questions

It is a draft from one sample. Keys that are optional in real data may look required here, and arrays with mixed shapes need human review. Always validate against real payloads.
Output includes $schema pointing to JSON Schema Draft 07, which most validators support well.
If every element matches the same inferred schema, a single items schema is used. If elements differ, the tool emits a oneOf listing up to several distinct shapes seen in the sample.
Yes, as a starting point alongside OpenAPI or hand-written descriptions. Refine enums, formats, and constraints the sample cannot infer.
No. Processing is entirely client-side in your browser.