JSON Schema Generator

Get a starting JSON Schema from an example payload in seconds.

Free
No sign-up
Runs in your browser

Schema title

Mark all fields required

Detect formats (email, date-time, uri…)

Sample JSON

JSON Schema (2020-12)

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "User",
  "type": "object",
  "properties": {
    "id": {
      "type": "integer"
    },
    "name": {
      "type": "string"
    },
    "email": {
      "type": "string",
      "format": "email"
    },
    "joined": {
      "type": "string",
      "format": "date-time"
    },
    "roles": {
      "type": "array",
      "items": {
        "type": "string"
      }
    },
    "address": {
      "type": "object",
      "properties": {
        "city": {
          "type": "string"
        },
        "postcode": {
          "type": "string"
        }
      },
      "required": [
        "city",
        "postcode"
      ],
      "additionalProperties": false
    },
    "active": {
      "type": "boolean"
    }
  },
  "required": [
    "id",
    "name",
    "email",
    "joined",
    "roles",
    "address",
    "active"
  ],
  "additionalProperties": false
}

Open file

Paste an array of examples to merge their shapes — fields missing from some items become optional.

Everything you type is processed in your browser. Nothing you enter is sent to our servers or stored by us.

How to use the JSON Schema Generator

Paste a sample JSON object, or an array of examples.
Choose whether every field is required and whether to detect formats.
Copy the schema and refine it.

What does this tool do?

JSON Schema validates API requests and responses, config files and form data, and powers editor autocompletion. Inferring it from a real example saves typing; with an array of examples, fields that are missing from some items are left optional and number types are widened where needed.

Everything runs in your browser — nothing you paste is uploaded.

Why use it?

Draft 2020-12.
Detects common formats.
Merges multiple examples.

Privacy

Everything you type is processed in your browser. Nothing you enter is sent to our servers or stored by us. There's no account to create and nothing to install.

Last reviewed October 4, 2026 by the M2Toolkit team.

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How to use the JSON Schema Generator

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Why use it?

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