What Is JSON? Simple Explanation, Examples and Uses

JSON stands for JavaScript Object Notation. It is a lightweight data format used to store and exchange structured information between apps, APIs and systems.

What does JSON mean?

JSON means JavaScript Object Notation. Although it came from JavaScript, JSON is now used across many programming languages.

JSON is popular because it is compact, readable and works naturally with modern web APIs.

Simple JSON example

Here is a simple JSON object:

{
  "name": "Jane Smith",
  "role": "Chief Cheese Tester",
  "active": true
}

This JSON object has three properties: name, role and active.

How JSON works

JSON is built from simple data structures.

JSON object example

A JSON object groups related values together using key-value pairs.

{
  "product": "Cheese Bridge Mug",
  "price": 12.99,
  "inStock": true
}

JSON array example

A JSON array stores multiple values in order.

{
  "tools": [
    "JSON Formatter",
    "JSON Viewer",
    "XML to JSON Converter"
  ]
}

Nested JSON example

JSON can contain nested objects and arrays.

{
  "company": {
    "name": "CheeseBridge",
    "team": [
      {
        "name": "Mia Cheese",
        "role": "Bridge Snack Coordinator"
      }
    ]
  }
}

What is JSON used for?

JSON vs XML

JSON and XML are both used to represent structured data. JSON is usually shorter and common in modern web APIs. XML is more verbose but supports attributes, namespaces and schema validation.

Read the full comparison: JSON vs XML

Common JSON mistakes

• Using single quotes instead of double quotes.
• Leaving a trailing comma after the last item.
• Forgetting a comma between properties.
• Using comments inside JSON.
• Not wrapping property names in double quotes.

Invalid JSON example

{
  "name": "Jane Smith",
  "role": "Chief Cheese Tester",
}

The example above is invalid because the last property has a trailing comma.

Trusted JSON references

Frequently asked questions

Related JSON guides