JSON (JavaScript Object Notation) is a lightweight data-interchange format that is easy to read and write for humans and machines alike. It is used extensively in web applications for exchanging data between the server and the client. While JSON is easy to read and write, it can become difficult to understand if the JSON object is complex and contains many nested objects and arrays. This is where a JSON formatter online comes in handy.

A JSON formatter online is a tool that takes a JSON object as input and formats it in a readable way so that it is easy to understand. It indents the JSON object to show the hierarchy of objects and arrays and adds line breaks to separate different elements. There are many JSON formatter tools available online that can be used for free.

One popular JSON formatter online is the JSON Formatter and Validator (https://www.tutsmake.com/online-json-viewer-or-formatter/). This tool allows users to enter their JSON object in a text box and then format it with the click of a button. The formatted JSON object is displayed in a new text box below the original text box. The tool also provides validation of the JSON object to ensure that it is well-formed and valid according to the JSON syntax.

Here's an example of how to use the JSON formatter online tool:

Let's say you have a JSON object like this:

    {
    "name": "John Smith",
    "age": 35,
    "address": {
        "street": "123 Main St.",
        "city": "Anytown",
        "state": "CA",
        "zip": "12345"
    },
    "phone": [
        {
            "type": "home",
            "number": "555-555-1212"
        },
        {
            "type": "work",
            "number": "555-555-2121"
        }
    ]
}

If you enter this JSON object into the JSON formatter and validator tool, it will format it like this:

    {
    "name": "John Smith",
    "age": 35,
    "address": {
        "street": "123 Main St.",
        "city": "Anytown",
        "state": "CA",
        "zip": "12345"
    },
    "phone": [
        {
            "type": "home",
            "number": "555-555-1212"
        },
        {
            "type": "work",
            "number": "555-555-2121"
        }
    ]
}

As you can see, the tool has indented the JSON object to show the hierarchy of objects and arrays. It has also added line breaks to separate different elements, making it much easier to read and understand.

In addition to the JSON Formatter and Validator, there are many other JSON formatter online tools available, each with their own features and capabilities. Some of these tools allow users to pretty-print the JSON object in different styles and formats, while others provide additional features like syntax highlighting and pre folding.

In conclusion, a JSON formatter online is an essential tool for developers and data analysts who work with JSON objects on a regular basis. It simplifies the task of understanding complex JSON objects by formatting them in a readable and structured way. There are many JSON formatter online tools available, each with its own features and capabilities, so users should choose the tool that best suits their needs.