Updated: March 07, 2025

.JSON File Extension

There is only one filetype that uses .JSON file extension and it is JavaScript Object Notation File.

JavaScript Object Notation File

File category:	Web Files
Developer:	Douglas Crockford
Open with:	Google Chrome (+11 more)
Platforms:	Windows, macOS, Linux, iOS, Android, ChromeOS, iPadOS

A JSON file is a text-based file format used to store and exchange data. It follows the JavaScript Object Notation (JSON) standard, which is a lightweight and easy-to-read format designed for structuring data. While it was originally based on JavaScript, JSON is now widely used across different programming languages.

JSON was first specified by Douglas Crockford in March 2001 as a way to facilitate real-time data exchange between servers and web applications. It was based on a subset of JavaScript (ECMA-262 3rd Edition, December 1999). The first official JSON standard (ECMA-404) was published in 2013, and updates have followed through organizations like the Internet Engineering Task Force (IETF) and ISO/IEC.

JSON is commonly used to transfer data between a server and a web application, making it a crucial part of APIs, web services, and modern applications. Some common examples include:

Web applications exchanging data with a server.
Storing configuration settings for software.
Saving and retrieving user data.
Structuring data in databases like MongoDB.
Mobile and desktop applications for storing lightweight data.

How to Open .JSON as JavaScript Object Notation File

Since JSON files contain plain text, they can be opened in any basic text editor. For better readability and formatting, there are many specialized JSON viewers and editors, including browser-based tools and plugins. Web browsers like Google Chrome, Firefox, and Edge can also display JSON data when used with developer tools.

JSON File Structure

JSON data is organized using key-value pairs. Each key is a string (inside double quotes), and the value can be a number, string, boolean (true/false), array, object, or null.

Example of a JSON object:

{
  "name": "Alice",
  "age": 25,
  "contact": {
    "email": "alice@example.com",
    "phone": "123-456-7890"
  },
  "skills": ["JavaScript", "Python", "SQL"],
  "active": true
}

JSON is often preferred over XML due to its simplicity and minimal formatting requirements. It is widely supported in programming languages like Python, JavaScript, Java, and many others.