json

.jsonJavaScript Object Notation

Douglas Crockford · 2001

Developer
Douglas Crockford
Category
Programming
MIME Type
application/json
First Released
2001
Open Format
Yes
File Signature
Plain text, starts with { or [
At a Glance
.json
JavaScript Object Notation

JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format that has become the standard for web APIs and configuration files.

Reviewed on April 28, 2026
Compression
Plain text
Transparency
N/A
Editability
High
Best for
editing in code tools

Key Features

  • Plain text storage behavior for typical code workflows
  • Common MIME type: application/json
  • Recognizable file signature: Plain text, starts with { or [
  • Associated with Douglas Crockford

Best For

  • Developer workflows
  • Version-controlled projects
  • Readable plain-text editing

Less Ideal For

  • Rich visual layouts
  • Binary asset storage
  • Non-technical end-user exchange

Common Use Cases

  • Writing source code
  • Configuring apps and tools
  • Automating workflows or scripting

How to Open It

  1. On Windows, open the file with VS Code or Notepad++.
  2. On macOS, open the file with VS Code or TextEdit.
  3. If the file does not open, confirm that the extension really matches .json and that the download or transfer completed without corruption.

What is a .json file?

JSON (JavaScript Object Notation) is a lightweight, text-based data interchange format that has become the standard for web APIs and configuration files. JSON uses human-readable key-value pairs and arrays, making it easy to parse by both humans and machines. It has largely replaced XML for data exchange due to its simplicity and smaller file sizes. JSON is supported by virtually every programming language and is essential for modern web development.

Programs That Open .json Files

PlatformProgram
WindowsVS CodeFree
Notepad++Free
Any text editorFree
macOSVS CodeFree
TextEditFree

Common Problems with .json Files

⚠️ Cannot open .json file
Install one of the recommended programs listed above. For a free option, try the first free program in the list.
⚠️ .json file is corrupted
Try re-downloading the file. If the file was transferred, ensure the transfer completed without errors.

Frequently Asked Questions

What program opens .json files?

.json files can be opened with several programs. VS Code is one of the most popular choices.

Is .json a safe file format?

Generally yes, .json files are safe to open with appropriate software.

Can I convert .json to another format?

Yes, there are many online and offline tools available to convert .json files. Check the conversion section above for specific methods.

Technical Details

JavaScript Object Notation files use the application/json MIME type and were first introduced in 2001 by Douglas Crockford. The file can be identified by its signature: Plain text, starts with { or [.

Did You Know?

JavaScript Object Notation was first released in 2001 by Douglas Crockford

Security Information

.json files are generally safe to open. However, always ensure your software is up to date to protect against potential vulnerabilities.

Related Extensions