JSON Formatter

Format, validate and beautify JSON data.

Indent:

Input JSON

Formatted output

{
  "name": "Alice",
  "age": 30,
  "hobbies": [
    "reading",
    "coding"
  ]
}

JSON syntax rules

JSON keys must be double-quoted strings. Values can be strings, numbers, booleans, null, objects, or arrays. No trailing commas, no comments.

Valid: {"key": "value", "n": 42}
Invalid: {key: 'value'} (unquoted key, single quotes)
Invalid: {"a": 1,} (trailing comma)
Invalid: // comments not allowed

What this tool does

Formats, validates and beautifies raw JSON text. Paste minified or messy JSON on the left and get a nicely indented, human-readable version on the right. Also highlights syntax errors with the exact error message.

Input fields explained

Input JSON

Paste any JSON here — minified, partially formatted, or from an API response. The formatter parses and re-serializes it.

Indent

2 spaces is the most common convention. 4 spaces is used in some style guides. Both are equally valid JSON.

Formula / How it works

Parses the JSON and re-serializes with proper indentation. Also validates the JSON and shows syntax errors.