JSON Pretty Print, Minify, and Validate

Format JSON for readability, minify it for compact storage, and validate it before using it in APIs, config files, frontend apps, or test fixtures. This tool is useful when debugging payloads, comparing responses, cleaning copied JSON, or shrinking data for transport and logging. ToolMill processes everything in your browser, making it a fast privacy-friendly option for working with sensitive JSON.

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Try it

Examples

Pretty-print JSON

Input

{"user":{"id":123,"name":"Ada"},"roles":["admin","editor"],"active":true,"meta":{"created":"2026-03-05T17:46:39Z"}}

Output

{
  "user": {
    "id": 123,
    "name": "Ada"
  },
  "roles": [
    "admin",
    "editor"
  ],
  "active": true,
  "meta": {
    "created": "2026-03-05T17:46:39Z"
  }
}

Minify JSON

Input

{
  "a": 1,
  "b": [2, 3],
  "nested": {
    "ok": true,
    "note": "hello"
  }
}

Output

{"a":1,"b":[2,3],"nested":{"ok":true,"note":"hello"}}

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JSON ↔ YAML Converter

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JSON Validator

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