ToolBox

JSON Validator

Check whether your JSON is valid, with a clear error if it is not.

{
"id": 1,
"name": "Ada Lovelace",
"active": true
}
Your file never leaves this browser tab — everything runs locally on your device.

How to use json validator

  1. Paste your JSON into the editor.
  2. Click "Validate".
  3. See a plain-language confirmation if it's valid, or the exact parse error if it isn't.

Common use cases

  • Checking a config file or API payload before using it in code.
  • Confirming a hand-edited JSON file didn't introduce a syntax error.
  • Teaching or learning JSON syntax by seeing exactly what breaks it.

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Frequently asked questions