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
- 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
- Open VS Code
- Go to Extensions (
Ctrl+Shift+X
)
- Search for "HTML Preview Pro"
- Click Install
- Open any HTML file - you're ready!
First Use
- Open an HTML file in VS Code
- Press
Ctrl+Shift+V
for side preview or Ctrl+Shift+H
for full preview
- Or use the preview button in the editor toolbar
- Watch live changes as you edit your code
- 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)
- 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
- 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
}
Default: true
Inject developer tools and error overlay:
{
"htmlPreviewPro.injectDevTools": false
}
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
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
- ✅ 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
- 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. 🚀