Responsive Design Tester
Test your website across multiple device viewports with synchronized scrolling and screenshot capabilities
Website URL & Controls
Enter a URL to test across different device viewports
Preset Devices
Standard viewport sizes
Mobile
Mobile 320px
320×568
Mobile 375px
375×667
Mobile 414px
414×896
iPhone 12
390×844
Tablet
Tablet 768px
768×1024
Tablet 1024px
1024×1366
iPad
820×1180
Desktop
Desktop 1280px
1280×720
Desktop 1440px
1440×900
Desktop 1920px
1920×1080
Desktop
1920×1080
Custom Devices
Add your own viewport sizes
Quick Actions
Common device combinations
Features & Usage Tips
✨ Key Features:
- • Exact viewport sizes: 320px, 375px, 414px (mobile)
- • Tablet sizes: 768px, 1024px
- • Desktop sizes: 1280px, 1440px, 1920px
- • Custom dimensions: Add your own viewport sizes
- • Synchronized scrolling: Scroll all viewports together
- • Device frames: Realistic device appearance
- • Portrait/Landscape: Toggle orientation
- • Zoom control: Scale viewports for better overview
- • Screenshot capability: Capture viewport images
🎯 Best Practices:
- • Test critical user flows on all viewport sizes
- • Check navigation and menu behavior
- • Verify text readability and button sizes
- • Test form layouts and input fields
- • Check image scaling and aspect ratios
- • Verify horizontal scrolling doesn't occur
- • Test touch targets are at least 44px
- • Check loading performance on mobile
🔒 CORS & Security Note:
Some websites may not load due to CORS (Cross-Origin Resource Sharing) restrictions or X-Frame-Options headers that prevent embedding in iframes. This is a security feature and not a limitation of this tool. Synchronized scrolling will only work for same-origin content. For best results, test with your own websites or sites that allow iframe embedding.