JSON Schema

Generate a JSON Schema from JSON

Create a JSON Schema from a sample document in seconds, edit it to fit your rules, and validate other JSON against it — without leaving the browser.

Open the schema generator → Free · No sign-up · Runs in your browser

How to use it

Paste a sample document into the editor.
Open Tools → Schema, choose a draft and click Generate from editor.
Review and edit the schema, then click Validate editor JSON to check documents against it.

Example

Sample JSON

{
  "id": 42,
  "name": "Ada",
  "tags": ["admin"]
}

Generated schema (Draft-07, excerpt)

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "type": "object",
  "properties": {
    "id": { "type": "integer", ... },
    "name": { "type": "string", ... },
    "tags": { "type": "array", "items": { "type": "string", ... } }
  },
  "required": ["id", "name", "tags"]
}

The generator also adds length and range limits based on the sample values. Loosen or remove them before using the schema for other documents.

Features

Three drafts

Generate Draft 2020-12, Draft-07 or Draft-04 schemas.

Types and required fields

Property types, array item types and required keys are inferred from the sample.

Validate

Check the editor JSON against any schema and see a detailed report.

Bring your own schema

Paste an existing schema to validate documents against it.

Frequently asked questions

Which JSON Schema drafts are supported?

Draft 2020-12, Draft-07 and Draft-04. Pick one before generating.

Why does validation fail on a different document?

Generated schemas include limits taken from your sample, such as exact string lengths and number ranges. Edit or remove them to allow other values.

Can I validate against my own schema?

Yes. Paste your schema into the schema box and click Validate editor JSON.

Is my data private?

Yes. Generation and validation run locally in your browser.