TULKIT

JSON Validator - Check & Format JSON Online

Validate and format your JSON data instantly with our free online JSON Validator. Detect syntax errors, check structure integrity, and beautify JSON for better readability.

Why Validate Your JSON?

  • API Debugging: Ensure your API payloads are properly formatted
  • Config Validation: Check JSON configuration files before deployment
  • Precise Error Location: Find exactly where the JSON is broken
  • Auto-Formatting: Beautify minified JSON for easier reading

Common Use Cases

🔌 API Development

Validate request/response payloads during testing.

⚙️ Config Files

Check package.json, tsconfig.json, and other configs.

📊 Data Import

Validate JSON data before database imports.

🔄 Data Exchange

Ensure JSON from third parties is well-formed.

How to Use This Tool

  1. Paste Your JSON: Enter the JSON data you want to validate.
  2. Click "Validate JSON": Our tool parses and checks your JSON.
  3. View Results: See if valid, or get error details with location.

💡 Tip: The formatted output shows your JSON with proper indentation, making it easier to read and debug.

JSON Validator Tool

Results will appear here after validation...

JSON Syntax Rules

Valid JSON must follow these rules:

  • Double Quotes: All strings and keys must use double quotes ("not 'single')
  • No Trailing Commas: Last item in arrays/objects can't have a comma
  • Proper Nesting: All brackets and braces must be properly closed
  • Valid Data Types: String, Number, Boolean (true/false), null, Object, Array
  • No Comments: JSON doesn't support // or /* */ comments
  • No Functions: Functions and undefined are not valid JSON values

Common JSON Errors

  • {key: "value"} - Key not in double quotes
  • {'key': 'value'} - Single quotes instead of double
  • {"items": [1, 2, 3,]} - Trailing comma after last element
  • {"data": undefined} - undefined is not valid JSON

JSON vs JavaScript Objects

While JSON is based on JavaScript object syntax, there are important differences. JavaScript objects allow single quotes, trailing commas, unquoted keys, and comments - none of which are valid in JSON.

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