Is my JSON uploaded anywhere?

No. Parsing and formatting happen with the browser's built-in JSON engine on your device. Nothing is sent to a server.

Why does my JSON fail with 'Unexpected token'?

The most common causes are trailing commas, single quotes instead of double quotes, unquoted keys and comments. JSON allows none of these.

How large a document can I format?

It depends on your device's memory, but documents of a few megabytes format almost instantly on a modern machine.

What's the difference between formatting and minifying?

Formatting adds indentation and line breaks for human readability. Minifying removes all unnecessary whitespace to reduce file size, which is useful for storage or transmission.

JSON Formatter

Format, beautify and validate JSON with clear error messages.

Input

JSON input

{"name":"John","age":25,"skills":["Python","AWS"]}

Output

Result

{
  "name": "John",
  "age": 25,
  "skills": [
    "Python",
    "AWS"
  ]
}

Valid JSON.

About JSON Formatter

JSON is easy for machines to read but painful for humans when it arrives minified on a single line. This formatter re-indents your JSON so nesting, arrays and object boundaries become obvious at a glance.

Formatting also acts as a syntax check: if the document cannot be parsed you get the exact position of the problem instead of a generic failure. Use Minify when you need the smallest possible payload for an API request or a config value.

How to use JSON Formatter

1Paste or paste your JSON into the text area
2If your JSON is valid, it will be formatted and prettified automatically
3If there are syntax errors, the exact position and nature of the error will be highlighted
4Use the Minify toggle to compress the JSON into a single line for smaller payloads
5Copy the formatted result and use it in your application

Example

Minified API Response

Input

{"user":{"id":123,"name":"John","email":"john@example.com"},"status":"active"}

Output

{
  "user": {
    "id": 123,
    "name": "John",
    "email": "john@example.com"
  },
  "status": "active"
}

When to use JSON Formatter

Formatting JSON API responses for readability during debugging
Validating JSON configuration files before deploying
Minifying JSON payloads to reduce API request size
Identifying syntax errors in manually-edited JSON
Converting minified logs into readable format for analysis

Common errors & troubleshooting

SyntaxError: Unexpected token ' in JSON at position 0

JSON only supports double quotes, not single quotes. Change 'key': 'value' to "key": "value"

SyntaxError: Unexpected token , in JSON at position 42

Remove trailing commas. JSON does not allow a comma after the last item in an object or array.

SyntaxError: Unexpected token u in JSON at position 0 (when parsing undefined)

JSON does not support undefined. Replace undefined with null if you need to represent an empty value.

Limitations & details

Maximum input size depends on your browser's memory, but typically handles files up to several MB
Comments are not part of the JSON spec and will cause validation errors
Duplicate keys in objects are allowed by JSON spec but often indicate a data error