JSON Formatter

A small, fast developer utility for formatting, validating, minifying, and copying JSON directly in your browser.

Features

• Pretty-print JSON with 2 spaces, 4 spaces, or tabs
• Minify JSON into compact output
• Validate JSON with useful parse errors and approximate line/column information when the browser provides a position
• Copy formatted output with temporary feedback
• Clear input and output instantly
• Load a realistic nested example
• Keyboard-friendly editing, including Tab indentation and Ctrl/Cmd + Enter to format
• Client-side JSON processing — input is not uploaded or stored by the application
• A 5,000,000-character client-side safety limit to keep very large inputs responsive
• Responsive dark-first UI for desktop and mobile

Tech Stack

• Laravel 13
• PHP 8.3+
• Blade
• Tailwind CSS 4
• Vite
• Vanilla JavaScript
• PHPUnit
• Node.js built-in test runner

Installation

git clone <repository-url>
cd json-formatter
composer install
cp .env.example .env
php artisan key:generate
npm install
npm run build
php artisan serve

Open http://localhost:8000 in your browser.

Usage

1. Paste JSON into the Input editor.
2. Choose an indentation style when formatting.
3. Use Format to prettify JSON or Minify to compact it.
4. Use Validate to check the input without changing it.
5. Use Copy to copy the current output.
6. Use Load Example for a ready-to-edit nested JSON sample.
7. Use Clear to reset the editor and output.

All JSON processing happens in the browser through the native JSON.parse() and JSON.stringify() APIs.

Development

Run the Laravel server and Vite dev server separately:

php artisan serve
npm run dev

For a production asset build:

npm run build

Testing

PHP tests:

php artisan test

JavaScript utility tests:

npm run test:js

Run both suites through Composer:

composer test

License

This project is licensed under the MIT License.