em - PHP in WebAssembly

em is a complete PHP development environment that runs entirely in your browser or as a desktop application. It compiles PHP to WebAssembly, providing a sandboxed environment where you can write, test, and run PHP code without any server setup.

🚀 Try it Now

Launch em in your browser →

No installation required - just click and start coding PHP instantly!

✨ Features

🌐 Browser-Based IDE

• Full-featured code editor with syntax highlighting
• Multiple PHP versions (8.0, 8.1, 8.2, 8.3, 8.4, master)
• Real-time code execution
• Built-in virtual browser for testing web applications

📁 Virtual File System

• Complete file system simulation in memory
• Import/export projects as ZIP files
• Persistent storage across sessions
• Directory operations and file management

🔗 GitHub Integration

• Load projects directly from GitHub repositories
• Import from GitHub Gists
• Secret Token Support (avoids REST api limits)

🗄️ Database & Extensions

• SQLite database support
• ZIP archive handling
• Image processing (GD, JPEG, PNG)
• XML/DOM manipulation
• Compression (zlib, bz2)
• And many more PHP extensions

🖥️ Desktop Application

Download the desktop version for offline development (uses electron):

| OS | Arch | Format | Link | |:--------|:-----:|:----------:|:---------------------------------------------------------------------------------------------| | Linux | x64 | AppImage | Download | | Linux | arm64 | AppImage | Download | | Linux | x64 | zip | Download | | Linux | arm64 | zip | Download | | MacOS | x64 | dmg | Download | | MacOS | arm64 | dmg | Download | | MacOS | x64 | zip | Download | | MacOS | arm64 | zip | Download | | Windows | x64 | portable | Download | | Windows | x64 | setup | Download | | Windows | x64 | zip | Download |

Note: Electron builds need to be started with --no-sandbox to function properly; It's a good idea to create a launcher for your operating system that automatically starts the application with --no-sanbbox. This is an annoyance and limitation of electron-builder that I can't find a gracious way around ...

🛠️ Use Cases

Learning & Education

• Perfect for PHP tutorials and learning
• No need to set up XAMPP, WAMP, or local servers
• Safe sandbox environment for experimentation

Prototyping & Testing

• Quickly test PHP concepts and algorithms
• Test across multiple PHP versions instantly

Development & Debugging

• Portable development environment
• Test code behavior in isolation
• Debug without affecting your main system

🎯 Quick Start

1. Open em in your browser
2. Choose your PHP version from the dropdown
3. Write your PHP code in the editor
4. Click "Run Code" or press Ctrl+Enter
5. See the output instantly

🔧 For Developers

GitHub Action

Use em as a build pipeline for your PHP WebAssembly projects:

- uses: krakjoe/em@develop
  with:
    EM_PHP_DIR: ./php-src
    bake: all

See ACTION.md for detailed usage instructions.

API Integration

Embed PHP execution in your JavaScript applications:

// Execute PHP code
const result = Module.invoke('<?php echo "Hello from PHP!"; ?>');
console.log(result); // "Hello from PHP!"

// Work with the virtual file system
Module.vfs.put('/data.txt', new TextEncoder().encode('Hello World'));
const content = Module.vfs.get('/data.txt');

📚 Advanced Features

Virtual Browser

• Run PHP web applications in a simulated browser environment
• Test forms, sessions, and HTTP requests
• Debug web applications without a real server

Project Management

• New File/Folder: Create and organize your project structure
• Import/Export VFS: Upload/Download and persist with native, optionally compressed, and random access memory streams.
• Import/Export ZIP: Upload/Download from external sources
• GitHub Import: Load repositories and gists directly

VFS Images

While ZIP is a perfectly cromulent and portable format, it's rather wasteful, and does not lend itself to very fast reading or writing, so we could not base persistence on Zip.

Instead em implements streaming the vfs as a contiguous buffer, the buffer will use compression where zlib is available, is randomly accessible, produces smaller outputs than zip and is much more suitable for persistence.

So that you may create images outside of the ide, we provide php-em-vfs.js, this may be used to create and extract images from and into local directories.

Examples

To create /tmp/my.vfsi with the content of /path/to/my/files:

php-em-vfs.js --mode create --in /path/to/my/files --out /tmp/my.vfsi

To create /tmp/my.vfsi with the contents of /path/to/my/files where the root directory in the image is desired to be files:

php-em-vfs.js --mode create --in /path/to/my/files --out /tmp/my.vfsi --strip 2

To extra /tmp/my.vfsi into /tmp/vfsi.my (output directory must exist):

php-em-vfs.js --mode extract --in /tmp/my.vfsi --out /tmp/vfsi.my

Multiple PHP Versions

Test your code across different PHP versions to ensure compatibility:

• PHP 8.0 through 8.4
• Latest development version (master branch)

🏗️ Architecture

em is built on several key technologies:

• WebAssembly: Runs PHP natively in the browser
• Emscripten: Compiles PHP C code to WebAssembly
• Virtual File System: Complete POSIX-like file operations
• Service Workers: Enables the virtual browser functionality
• IndexedDB/FileSystem API: Provides persistent storage

🤝 Contributing

We welcome contributions! Whether you're:

• 🐛 Reporting bugs
• 💡 Suggesting features
• 📝 Improving documentation
• 🔧 Contributing code

Check out our issues to get started.

📄 License

This project is licensed under the PHP License 3.01 - see the LICENSE file for details.

🙏 Acknowledgments

• PHP Core Team for the amazing PHP language
• Emscripten team for WebAssembly tooling
• All contributors who help make em better

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Start coding PHP in your browser today! → Launch em