</>DevToolsHub
All tools / Data
Data

JSON Formatter

Processed on your device

Format, validate, and minify JSON.

JSON Formatter
Ready. Use the example or paste your own input.

How to use JSON Formatter

Paste JSON and choose Format for readable indentation or Minify for compact output. Invalid syntax is reported without changing your input.

Good to know

JSON requires double-quoted keys and strings. Trailing commas and comments are not valid JSON. JavaScript number precision applies; quote large identifiers to preserve them.

Clean up an API response

Choose Format to try this example.

Input

{"user":{"id":42,"active":true},"roles":["editor","viewer"]}

Expected result

{
  "user": {
    "id": 42,
    "active": true
  },
  "roles": [
    "editor",
    "viewer"
  ]
}

Common questions and mistakes

Why does my JSON fail validation?

Check for trailing commas, single quotes, or an unquoted key. For example, {"name":"Ada",} is invalid because of the final comma. JSON values must be strings, numbers, objects, arrays, true, false, or null.

Will formatting preserve every value?

Formatting parses and serializes the input. Duplicate keys keep their last value, and numbers use JavaScript precision. Put long account numbers and identifiers in quotes before processing. Use a text diff when exact preservation matters.

Related tools