🧩 JSON Formatter

How many times have you opened a messy JSON file that’s all on one line — or a config full of unordered keys and trailing commas?

JSON Formatter fixes that. A small but powerful utility that makes your data readable, organized, and consistent.

Online formatters can sometimes process your data through remote servers, which may pose a risk if you’re working with API keys, credentials, or sensitive configuration files. This extension runs entirely offline, inside your editor, keeping your data private and secure.

✨ Features

• 🎨 Beautify JSON — Add proper indentation and spacing
• 📦 Minify JSON — Compress JSON by removing extra whitespace
• 🔤 Sort Keys — Alphabetically sort object keys (optionally recursive)
• 🪄 Beautify & Sort — Combine both actions for perfect readability
• 💬 JSONC Support — Works with JSON files that include comments
• 🔧 Smart Indentation — Detects and preserves spaces or tabs
• 📝 Selection Formatting — Works on selected text or entire file
• ⚙️ Configurable — Customize sort behavior and notifications

🪄 Usage

Command Palette

1. Open Command Palette (Ctrl+Shift+P / Cmd+Shift+P)

2. Run one of:

   • JSON: Beautify
   • JSON: Minify
   • JSON: Sort Keys
   • JSON: Beautify & Sort

Context Menu

Right-click a .json or .jsonc file in:

• Explorer
• Editor
• Tab title → Select one of the available JSON Formatter actions.

Keyboard Shortcut

Shift+Alt+F (Windows/Linux) or Shift+Option+F (macOS) Triggers Beautify on the current file or selection.

Selection Formatting

Select a block of JSON text → Run any formatter command → Only that portion will be transformed.

⚙️ Configuration

You can tweak behavior in your VS Code settings:

{
  "jsonFormatter.sort.recursive": true,        // Sort nested objects
  "jsonFormatter.sort.caseInsensitive": true,  // Ignore case when sorting keys
  "jsonFormatter.showSuccessToast": false      // Show toast instead of status bar
}

🧠 How It Works

• Automatically detects indentation (tabs or spaces)
• Strips single-line (//) and multi-line (/* */) comments in JSONC
• Removes trailing commas before parsing
• Preserves your file’s original line endings (LF / CRLF)
• Validates and shows clear errors if JSON is invalid
• Applies edits safely and atomically — never breaks your file

💡 Examples

Beautify

Before

{"name":"John","age":30,"city":"New York"}

After

{
  "name": "John",
  "age": 30,
  "city": "New York"
}

Sort Keys

Before

{"zebra":1,"apple":2,"middle":3}

After

{"apple":2,"middle":3,"zebra":1}

JSONC Support

Before

{
  // App config
  "theme": "dark", // trailing comma
}

After

{
  "theme": "dark"
}

⚠️ Known Limitations

• Comments are removed when formatting (JSONC standard)
• Very large JSON files (>10MB) may take slightly longer to process

🧩 Installation

From Marketplace:

ext install swisstool.json-formatter-offline

From source:

git clone https://github.com/swisstool-io/vscode-json-formatter
cd vscode-json-formatter
npm ci
npm run compile
npm run build:test
npm test

🧪 Requirements

💻 Development

To run locally:

npm run compile
code .
# Press F5 to start the Extension Host

🛠️ Part of the SwissTool Collection

A set of small, focused developer tools for VS Code — each designed to solve one problem cleanly and get out of your way.

Explore more at swisstool.io.

🤝 Contributing

Open source contributions are welcome. If you’d like to improve this extension or report an issue, feel free to open a pull request or discussion.

See CONTRIBUTING.md (coming soon) for guidelines.

License: MIT © 2025 — made with ❤️ by Soufiane Rafik, part of Swisstool.io