HTML Preview Pro - Ultimate Live Preview & Responsive Testing

🚀 The most reliable HTML preview extension for VS Code - Never fails like other extensions!

A rock-solid, feature-rich VS Code extension that provides comprehensive HTML preview capabilities with live reload, responsive device testing, developer tools integration, and multi-browser support. Built from the ground up to be reliable, fast, and developer-friendly.

🎬 See It In Action

Live demonstration of HTML Preview Pro's responsive testing, live reload, and multi-device preview capabilities

✨ Why HTML Preview Pro?

🛡️ Rock-Solid Reliability

• Never fails to work - Comprehensive error handling and fallbacks
• Cross-platform tested - Works perfectly on Windows, Mac, and Linux
• VS Code compatibility - Tested across multiple VS Code versions
• Graceful degradation - Features work even if some components fail

🚀 Advanced Preview Features

• Live reload with smart diffing - Only reloads what changed
• Hot CSS reload - Update styles without full page refresh
• Multi-file support - Handles HTML files with external CSS/JS/images
• Local server integration - Proper asset resolution and CORS handling
• Auto-refresh on save - Instant updates as you type

📱 Responsive Design Testing

• Device presets: iPhone 14 Pro, iPad, Samsung Galaxy S23, Surface Pro, and more
• Custom viewports - Set any width/height for testing
• Pixel-perfect testing - Accurate device simulation with proper DPI
• Quick device switching - Toggle between devices instantly
• Orientation support - Portrait and landscape testing

🔧 Developer Tools Integration

• Browser console in VS Code - See console logs without leaving editor
• Error overlay - Visual error reporting with stack traces
• Network monitoring - Track resource loading and performance
• Source maps support - Debug with original source files
• Performance metrics - Loading times and bundle size analysis

🌐 Multi-Browser Support

• Smart browser detection - Opens in your preferred browser
• Chrome, Firefox, Edge, Safari - Full support for all major browsers
• Custom browser commands - Configure specific browser versions
• Private browsing mode - Test without cache/cookies

☕ Like This Extension?

Support its development and keep it free for everyone:

🚀 Installation

From VS Code Marketplace

1. Open VS Code
2. Go to Extensions (Ctrl+Shift+X)
3. Search for "HTML Preview Pro"
4. Click Install
5. Open any HTML file - you're ready!

First Use

1. Open an HTML file in VS Code
2. Press Ctrl+Shift+V for side preview or Ctrl+Shift+H for full preview
3. Or use the preview button in the editor toolbar
4. Watch live changes as you edit your code
5. Right-click for more options like responsive testing

📚 How to Use

Method 1: Keyboard Shortcuts (Recommended)

• Side Preview: Ctrl+Shift+V (Windows/Linux) or Cmd+Shift+V (Mac)
• Full Preview: Ctrl+Shift+H (Windows/Linux) or Cmd+Shift+H (Mac)
• Open in Browser: Ctrl+Shift+B (Windows/Linux) or Cmd+Shift+B (Mac)
• Refresh Preview: Ctrl+Shift+R (Windows/Linux) or Cmd+Shift+R (Mac)

Method 2: Editor Toolbar

• Click the 📱 Show Side Preview button in the HTML editor toolbar
• Click the 🖥️ Show Full Preview button for full-window preview
• Click the 🌐 Open in Browser button to launch external browser

Method 3: Command Palette

• Press Ctrl+Shift+P
• Type "HTML Preview Pro"
• Select your desired action

Method 4: Context Menu

• Right-click any HTML file in Explorer
• Select "Show Side Preview" or "Open in Browser"

📖 Detailed Features

Live Preview Panel

The preview panel provides a professional, feature-rich HTML viewing experience:

• Real-time updates - See changes instantly as you type
• Smart reload - Only updates changed content, preserves scroll position
• Error overlay - Visual feedback for HTML/CSS/JS errors
• Status indicators - Live reload status and connection health
• Zoom controls - Zoom in/out for detailed inspection

Responsive Testing Mode

Advanced responsive design testing capabilities:

• Device simulation - Accurate viewport and user agent simulation
• Preset devices - iPhone, iPad, Android, Surface, MacBook, iMac presets
• Custom viewports - Set any width/height combination
• DPI scaling - Proper high-DPI device simulation
• Touch simulation - Simulate touch interactions for mobile testing

Developer Console Integration

Built-in console for debugging without leaving VS Code:

• Console logs - View console.log, warn, error messages
• Error tracking - Automatic error capture with stack traces
• Network monitoring - Track HTTP requests and responses
• Performance metrics - Page load times and resource sizes
• Live filtering - Search and filter console output

Smart File Watching

Intelligent file monitoring for optimal performance:

• Selective watching - Only watches relevant file types
• Debounced updates - Prevents excessive reloads during rapid changes
• Glob pattern support - Customizable file patterns to watch
• Workspace-aware - Automatically detects workspace structure
• Memory efficient - Optimized watching with minimal resource usage

⚙️ Configuration

Access settings via File > Preferences > Settings and search for "HTML Preview Pro":

Core Settings

htmlPreviewPro.autoReload

Default: true Enable/disable automatic preview refresh when files change:

{
  "htmlPreviewPro.autoReload": false
}

htmlPreviewPro.autoReloadDelay

Default: 500 Delay in milliseconds before auto-reloading (prevents excessive reloads):

{
  "htmlPreviewPro.autoReloadDelay": 1000
}

htmlPreviewPro.openInExternalBrowser

Default: "default" Choose which browser to use for "Open in Browser" command:

{
  "htmlPreviewPro.openInExternalBrowser": "chrome"
}

Options: "default", "chrome", "firefox", "edge", "safari"

Responsive Testing Settings

htmlPreviewPro.defaultDevice

Default: "desktop" Default device preset for responsive testing:

{
  "htmlPreviewPro.defaultDevice": "iPhone 14 Pro"
}

Options: "desktop", "iPhone 14 Pro", "iPhone SE", "iPad", "Samsung Galaxy S23", "Surface Pro", "MacBook Pro 13", "MacBook Pro 16", "iMac 24"

Developer Features

htmlPreviewPro.showConsole

Default: false Show browser console panel in preview:

{
  "htmlPreviewPro.showConsole": true
}

htmlPreviewPro.injectDevTools

Default: true Inject developer tools and error overlay:

{
  "htmlPreviewPro.injectDevTools": false
}

htmlPreviewPro.preserveScrollPosition

Default: true Preserve scroll position when reloading preview:

{
  "htmlPreviewPro.preserveScrollPosition": false
}

Advanced Settings

htmlPreviewPro.customCSS

Default: "" Custom CSS to inject into preview for debugging:

{
  "htmlPreviewPro.customCSS": "* { outline: 1px solid red !important; }"
}

htmlPreviewPro.watchFilePatterns

Default: ["**/*.html", "**/*.css", "**/*.js", "**/*.png", "**/*.jpg", "**/*.jpeg", "**/*.gif", "**/*.svg"] File patterns to watch for changes:

{
  "htmlPreviewPro.watchFilePatterns": [
    "**/*.html",
    "**/*.css",
    "**/*.js",
    "src/**/*.json"
  ]
}

htmlPreviewPro.serverPort

Default: 0 Custom port for local server (0 = auto-assign):

{
  "htmlPreviewPro.serverPort": 3000
}

htmlPreviewPro.enableHTTPS

Default: false Enable HTTPS for local server (useful for testing secure features):

{
  "htmlPreviewPro.enableHTTPS": true
}

🎯 Use Cases & Examples

Frontend Development

Perfect for building modern web applications:

• Live reload - See changes instantly while coding
• Responsive testing - Test mobile/tablet layouts without external tools
• Asset debugging - Verify images, fonts, and resources load correctly
• CSS development - Hot reload CSS without losing application state

Web Design & Prototyping

Ideal for designers and frontend developers:

• Design testing - Test layouts across multiple device sizes
• Client presentations - Show work in real-time during meetings
• Cross-browser testing - Verify compatibility across browsers
• Portfolio development - Perfect preview for personal websites

Static Site Development

Great for static site generators and simple websites:

• Jekyll/Hugo sites - Preview generated HTML files
• Landing pages - Test marketing pages and forms
• Documentation sites - Preview docs with proper styling
• Portfolio sites - Test personal/company websites

Educational Use

Perfect for learning web development:

• HTML/CSS tutorials - Instant feedback while learning
• JavaScript debugging - See console output in VS Code
• Responsive design education - Learn mobile-first development
• Web standards teaching - Demonstrate best practices

🔧 Advanced Features

Screenshot & Recording

Capture your work for documentation and sharing:

• High-quality screenshots - Capture any device size
• Full-page screenshots - Capture long pages completely
• Multiple formats - PNG, JPEG, WebP support
• Custom dimensions - Screenshot specific viewport sizes

Performance Monitoring

Built-in performance analysis tools:

• Load time tracking - Monitor page load performance
• Resource size analysis - Track CSS/JS/image sizes
• Network waterfall - Visualize resource loading order
• Core Web Vitals - Monitor LCP, FID, CLS metrics

Security Features

Safe development environment:

• Local-only server - No external network access required
• CORS handling - Proper cross-origin resource sharing
• Content Security Policy - CSP header support for testing
• HTTPS testing - Test secure features locally

🆘 Troubleshooting

Preview Not Loading

• ✅ Ensure you have an HTML file open or selected
• ✅ Check that the file exists and is readable
• ✅ Verify VS Code has file system permissions
• ✅ Try refreshing the preview with Ctrl+Shift+R

Live Reload Not Working

• ✅ Check that htmlPreviewPro.autoReload is enabled in settings
• ✅ Verify the file is within the watch patterns
• ✅ Try manually refreshing the preview
• ✅ Check the output panel for WebSocket connection errors

External Browser Not Opening

• ✅ Verify the selected browser is installed
• ✅ Check htmlPreviewPro.openInExternalBrowser setting
• ✅ Try using "default" browser setting
• ✅ Ensure file permissions allow opening external applications

Responsive Mode Issues

• ✅ Check if device preset is supported
• ✅ Try switching to desktop mode and back
• ✅ Verify viewport meta tag in your HTML
• ✅ Clear browser cache if using external browser

Port Conflicts

• ✅ Change htmlPreviewPro.serverPort to a different port
• ✅ Check if other applications are using the port
• ✅ Use port 0 for automatic port assignment
• ✅ Restart VS Code if port issues persist

Performance Issues

• ✅ Reduce htmlPreviewPro.autoReloadDelay for faster updates
• ✅ Limit htmlPreviewPro.watchFilePatterns to essential files
• ✅ Disable console panel if not needed
• ✅ Close unused preview panels

📄 License

MIT License - see LICENSE file for details.

🤝 Contributing

Contributions are welcome! Please feel free to submit issues and enhancement requests.

Planned Features

• 🎬 Screen recording - Record interactions for demos
• 🌍 Multi-language support - Internationalization support
• 🔄 Git integration - Compare previews across branches
• 📊 Analytics dashboard - Detailed performance metrics
• 🤖 AI-powered suggestions - Accessibility and performance tips
• 📱 Mobile app testing - Real device testing integration

📝 Changelog

Version 1.0.0

• ✨ Initial release with rock-solid reliability
• 🚀 Live reload with WebSocket integration
• 📱 Responsive device testing with accurate presets
• 🔧 Developer console integration
• 🌐 Multi-browser support
• ⚙️ Comprehensive configuration options
• 🛡️ Robust error handling and recovery
• 📚 Extensive documentation and examples

🔥 What Makes This Extension Different?

Reliability First

Unlike other HTML preview extensions that fail frequently, HTML Preview Pro is built with reliability as the top priority:

• ✅ Comprehensive error handling - Never crashes or fails silently
• ✅ Cross-platform testing - Works identically on Windows, Mac, Linux
• ✅ Version compatibility - Tested across VS Code versions
• ✅ Graceful degradation - Core features work even if advanced features fail
• ✅ Detailed logging - Easy troubleshooting with comprehensive output

Modern Architecture

Built with modern web technologies and best practices:

• 🏗️ TypeScript codebase - Type-safe and maintainable
• 🚀 Express.js server - Reliable local development server
• 🔌 WebSocket integration - Real-time communication for live reload
• 👀 Chokidar file watching - Efficient file system monitoring
• 🎨 CSS Grid/Flexbox layouts - Modern, responsive preview interface

Developer Experience

Designed by developers, for developers:

• 🎯 Intuitive keyboard shortcuts - Optimized for productivity
• 📱 Accurate device simulation - Pixel-perfect responsive testing
• 🔍 Comprehensive debugging - Console, errors, and performance in one place
• ⚡ Lightning fast - Optimized for speed and minimal resource usage
• 📚 Extensive documentation - Everything you need to know

💡 Pro Tips

Maximizing Productivity

• Use Ctrl+Shift+V for side-by-side editing and preview
• Enable console panel for real-time JavaScript debugging
• Set up custom CSS for visual debugging (outline all elements)
• Use responsive mode to test mobile layouts without external tools

Performance Optimization

• Adjust auto-reload delay for your typing speed
• Limit watch patterns to only necessary file types
• Use HTTPS mode for testing service workers and secure features
• Enable hot CSS reload for faster style iteration

Team Collaboration

• Share preview URLs with team members for quick reviews
• Use screenshot feature for design documentation
• Test with multiple device presets for comprehensive coverage
• Document responsive breakpoints using the device info display

Made with ❤️ for developers who demand reliability and functionality!

Note: This extension works out of the box - no configuration required. Just install and start previewing!

☕ Support This Extension

If HTML Preview Pro has improved your development workflow and saved you time, consider supporting its development:

Your support helps:

• ✨ Keep the extension free for everyone
• 🚀 Fund new features and improvements
• 🐛 Fix bugs and maintain compatibility
• 📚 Create better documentation and tutorials
• 🔧 Add enterprise features and professional tools

Thank you for using HTML Preview Pro! 🙏

🌟 Reviews

"Finally, an HTML preview extension that actually works! No more crashes or failed loads. The responsive testing is amazing!" - Frontend Developer

"The live reload is so smooth, and the device presets are spot-on. This has become essential for my workflow." - Web Designer

"I love the console integration. Debugging HTML/CSS/JS without leaving VS Code is a game-changer." - Full-Stack Developer

"Reliable, fast, and feature-rich. Everything other extensions should have been." - Senior Developer

HTML Preview Pro - Because reliability matters. 🚀