JSON Formatter & Validator

Format, validate, beautify, and inspect JSON with clear syntax error diagnostics.

Your tool input is processed locally in your browser and is not sent to our servers.

Indent:

Raw JSON Input

Formatted Output Valid JSON

{
  "product": "Tools by nbsumit",
  "version": 1,
  "features": [
    "privacy",
    "speed",
    "zero-server-storage"
  ],
  "active": true
}

What this tool does

Validates JSON syntax and formats code with customizable indentation (2 spaces, 4 spaces, or tabs). Pinpoints syntax errors with line and column numbers.

How to use this tool

Paste your raw or unformatted JSON into the editor.
Select your preferred indentation level.
View the highlighted formatted JSON or detailed error feedback explaining any syntax issues.
Copy or download the formatted JSON file.

Practical Examples

Formatting Compact API Response

Turn a single-line payload into structured JSON.

Input: {"status":"ok","code":200,"items":["a","b"]}

Output: { "status": "ok", "code": 200, "items": [ "a", "b" ] }

Important Note: Standard JSON does not allow trailing commas, single-quoted strings, or undefined values.

Frequently Asked Questions

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