Free JSON Formatter Online

{"id":42,"name":"Ada Lovelace","active":true,"roles":["admin","editor"],"meta":{"created":"2024-01-15T09:30:00Z","score":98.5}}

{
  "id": 42,
  "name": "Ada Lovelace",
  "active": true,
  "roles": [
    "admin",
    "editor"
  ],
  "meta": {
    "created": "2024-01-15T09:30:00Z",
    "score": 98.5
  }
}

The data is untouched — only whitespace changed. Nested objects and arrays each gain a level of indentation, which is what makes the structure scannable. Formatting is purely presentational, so you can safely paste the result back into the system it came from.

{
  "name": "checkout-service",
  "retries": 3,
}

Expected double-quoted property name — line 4, column 1

The comma after 3 on line 3 is the mistake, but the error points at line 4. That is not a bug: the parser accepts the comma, then expects another property name and instead finds the closing brace, so the first position it can definitively call invalid is line 4. When a reported line looks fine, the cause is almost always the line above it.

{
  "id": 42,
  "name": "Ada Lovelace",
  "active": true,
  "roles": [
    "admin",
    "editor"
  ],
  "meta": {
    "created": "2024-01-15T09:30:00Z",
    "score": 98.5
  }
}

{"id":42,"name":"Ada Lovelace","active":true,"roles":["admin","editor"],"meta":{"created":"2024-01-15T09:30:00Z","score":98.5}}

Minifying this example drops it from 176 bytes to 127, a 28% reduction, entirely from removing whitespace. The saving scales with nesting depth, so deeply structured documents benefit most. Over HTTP with gzip or brotli the real-world difference is smaller, since compression already handles repeated indentation well.