Codex Dev

Developer's Insight Tool - View your website in multiple responsive screen sizes simultaneously with synchronized scrolling.

Codex Dev is the ultimate responsive design testing tool for web developers. View your website across multiple device screen sizes simultaneously in a single, organized tab. ### ✨ Key Features **🖥️ Multi-Device Testing** - View iPhone, iPad, and Desktop sizes side-by-side - Test multiple breakpoints at once - Quick launch presets for common device combinations **📱 Comprehensive Device Library** - Mobile: iPhone 14 Pro, iPhone SE, Samsung Galaxy S23, Pixel 7 - Tablet: iPad Pro 12.9", iPad Air, iPad Mini, Surface Pro 7 - Desktop: 1366x768, 1920x1080, 2560x1440, 4K (3840x2160) - Custom sizes: Enter any dimensions (min 320px) **🎯 Smart Hybrid Approach** - Iframe-first: All devices in one tab when possible - Automatic fallback: Opens popup windows for iframe-blocking sites - Works with ALL websites including Facebook, Twitter, and more **⚙️ Powerful Controls** - 🔄 Rotate devices (portrait ↔ landscape) - ↻ Refresh individual or all viewports - 🔗 Synchronized scrolling across all devices - 📸 Screenshot capture for each viewport **🎨 Premium Interface** - Modern dark mode design - Clean, organized layout - Smooth animations - Responsive grid that adapts to your screen ### 🚀 Perfect For - Frontend developers testing responsive designs - QA engineers validating cross-device compatibility - Designers reviewing breakpoint implementations - Anyone building mobile-first websites ### 🔒 Privacy First - All data stored locally on your device - No external servers or analytics - No data collection or tracking - Open source and transparent ### 📖 How to Use 1. Click the Codex Dev icon in your toolbar 2. Select a quick launch preset or individual devices 3. Enter the URL you want to test 4. View your site across all selected devices instantly ### 🆓 Completely Free No subscriptions, no hidden fees, no premium tiers. Built by developers, for developers. --- **Made with ❤️ for the web development community**