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JSON Validator

A real-time JSON validator and formatter. Paste your JSON content below to validate syntax and see the formatted structure.

How to Use

  1. Paste JSON: Enter your JSON content in the text area below
  2. Real-time Validation: See immediate feedback on syntax errors
  3. Formatted Output: View the properly formatted JSON structure
Enter JSON content above to see the formatted result...

Features

  • Real-time Validation: Instant feedback as you type
  • Syntax Highlighting: Clear error messages for invalid JSON
  • Pretty Formatting: Automatically format valid JSON
  • Responsive Design: Works on desktop and mobile devices

Privacy & Security

🔒 100% Client-side: All processing happens in your browser. No data is sent to any server or saved anywhere.

Common JSON Structure

{
  "string": "value",
  "number": 42,
  "boolean": true,
  "null": null,
  "array": [
    "item1",
    "item2",
    "item3"
  ],
  "object": {
    "nested": "value",
    "deep": {
      "level": 3
    }
  }
}

JSON Syntax Rules

  • Strings: Must be enclosed in double quotes
  • Numbers: Can be integers or decimals
  • Booleans: true or false (lowercase)
  • Null: null (lowercase)
  • Arrays: Enclosed in square brackets []
  • Objects: Enclosed in curly braces {}
  • Commas: Separate elements, no trailing comma
  • Quotes: Property names must be in double quotes

Common Errors

Error Cause Fix
Unexpected token Missing quotes around strings Use "value" instead of value
Unexpected end of JSON Missing closing bracket/brace Check all brackets are closed
Unexpected number Number at start of object Add property name: "key": 123
Trailing comma Comma after last element Remove trailing comma