Responsive Breakpoint Tester
Test website responsiveness across multiple device breakpoints instantly
Note: Some websites may block iframe embedding (X-Frame-Options)
About Responsive Tester
Responsive design is essential for modern websites. Our Responsive Breakpoint Tester allows developers and designers to quickly preview how their site looks across different device sizes without needing multiple physical devices.
Common Breakpoints
- Mobile: 320px - 480px
- Tablet: 481px - 768px
- Laptop: 769px - 1024px
- Desktop: 1025px - 1200px
- Large Screens: 1201px+
Simply enter your URL and switch between presets to verify your layout, typography, and images scale correctly.
Frequently Asked Questions
Many major websites (like Google, Facebook) block their content from being displayed inside iframes for security reasons (X-Frame-Options header). This tool works best for testing your own sites during development or sites that allow embedding.
This tool simulates viewport sizes but cannot emulate specific device hardware, touch events, or browser-specific rendering quirks. For final testing, always check on actual devices.
Yes, as long as your local server is running and accessible (e.g., http://localhost:3000), you can enter the local URL to test your development build.
While we provide presets, you can't manually input custom dimensions in this version. However, you can use the browser's developer tools (F12) for pixel-perfect custom resizing.
No, this tool only resizes the viewport. It does not change the User-Agent string sent to the server, so server-side device detection might not trigger mobile views if they rely solely on User-Agent.