JSON Formatter

JSON (JavaScript Object Notation) is a text-based data format used by virtually every web API, configuration file, and data exchange pipeline. Raw JSON from APIs often comes as a single minified line — valid but unreadable. A JSON formatter (also called JSON prettifier or JSON beautifier) adds indentation and line breaks so you can actually read and debug the data.

Minification does the reverse: it strips all unnecessary whitespace to reduce payload size. A typical API response can shrink 30-50% when minified, which matters for bandwidth-sensitive applications, mobile clients, and large dataset transfers.

Validation checks whether the JSON is syntactically correct according to the JSON specification. Common errors include trailing commas, single quotes instead of double quotes, unquoted keys, and missing brackets. The validator here shows the exact line and column where parsing fails.

Paste minified JSON like this:

{"users":[{"id":1,"name":"Alice","email":"[email protected]","active":true},{"id":2,"name":"Bob","email":"[email protected]","active":false}],"total":2}

The formatter produces readable output:

{
  "users": [
    {
      "id": 1,
      "name": "Alice",
      "email": "[email protected]",
      "active": true
    },
    {
      "id": 2,
      "name": "Bob",
      "email": "[email protected]",
      "active": false
    }
  ],
  "total": 2
}

The tree view lets you collapse and expand nested objects, which is useful when working with large API responses that have hundreds of keys.

Is this JSON formatter safe to use with sensitive data?

Yes. All processing happens in your browser using the native JSON.parse() and JSON.stringify() APIs. Your JSON is never sent to a server, never logged, and never leaves your device.

How do I fix "Unexpected token" errors in JSON?

The most common causes are: trailing commas after the last item in an array or object, single quotes instead of double quotes around strings, unquoted property names, comments (JSON does not support comments), and missing closing brackets or braces. The error indicator shows the exact position where the parser stopped.

What is the difference between JSON formatting and JSON validation?

Validation checks whether your JSON is syntactically correct — can it be parsed without errors? Formatting takes valid JSON and reformats it with consistent indentation for readability. Minification is the opposite of formatting — it removes all whitespace to make the JSON as compact as possible.

Can I format large JSON files here?

The editor handles files up to a few megabytes comfortably. For very large files (10MB+), browser performance may degrade. In that case, consider using a CLI tool like jq or python -m json.tool.