Data tool

JSON Validator

Paste JSON or drag in a .json file to check whether it parses cleanly, find syntax errors, and inspect the top-level structure.

Runs Locally

This tool runs in your browser. Files never leave your device.

JSON input

Drop a .json file here or paste raw JSON below.

Open file

Drag and drop a JSON file anywhere inside this input card.

Validation result

This JSON parses successfully.

Valid JSON

No syntax errors found. This file can be parsed with JSON.parse.

Type

Object

Size

243 B

Top-level items

Total values

Parsed preview

{
  "project": "FreeProTool",
  "valid": true,
  "items": [
    {
      "name": "JSON Validator",
      "type": "Data tool"
    },
    {
      "name": "JSON Formatter",
      "type": "Data tool"
    }
  ],
  "settings": {
    "clientOnly": true,
    "dragAndDrop": true
  }
}

What this tool does

JSON Validator checks JSON syntax and structure to help identify formatting mistakes before they cause problems. Quickly detect missing commas, unmatched brackets, invalid values, and other common JSON errors. This tool is useful for developers, API integrations, automation workflows, and data validation tasks.