Responsive Design Tester - Test Your Website on Any Screen Size
Use this powerful tool to test how your website responds to different screen sizes and devices. Select preset device dimensions or enter custom sizes to see how your site adapts to different screens.
Note: Some websites may not display due to security restrictions.
Device Presets
Custom Size
Responsive Design Tips
Why Responsive Design Matters
With the increasing use of mobile devices, responsive design has become essential for modern web development. Google's mobile-first indexing prioritizes mobile-friendly websites in search results, making responsive design crucial for SEO success. Responsive websites automatically adjust their layout to fit different screen sizes, from smartphones to tablets to desktop monitors, providing optimal user experience across all devices. This approach significantly improves conversion rates by ensuring users can easily navigate and interact with your content regardless of their device. As mobile traffic continues to grow and represents over 50% of global web traffic, implementing responsive design is no longer optional—it's necessary to reach and engage the expanding mobile user base effectively.
Common Breakpoints
- Mobile: 320px - 480px
- Tablet: 768px - 1024px
- Desktop: 1025px - 1440px
- Large Screen: 1441px and above
Testing Tips
- Test with real content instead of placeholders to ensure layouts handle various content lengths
- Check that navigation menus are usable on small screens
- Ensure form elements are usable and easy to fill out on all devices
- Test touch interactions to ensure tap targets are large enough
- Check that images and media scale correctly
- Test loading performance on simulated slow networks (like 3G) to ensure optimal mobile experience
- Verify font readability by ensuring text size and line height remain legible on the smallest mobile screens
- Validate interactive elements by confirming buttons and links have adequate spacing to prevent accidental taps on touch devices
Frequently Asked Questions
Many websites set X-Frame-Options or Content-Security-Policy headers for security reasons, which prevent them from being loaded in iframes. This is a security measure to prevent clickjacking and other attacks. For these websites, you may need to use browser developer tools or other methods for testing.
This tester primarily simulates different screen sizes but cannot fully replicate all features of real devices, such as touch interactions, device pixel ratios, or specific browser behaviors. For final testing, it's recommended to verify your designs on actual devices.
Use the custom size feature to input your media query breakpoint values. For example, if you have a breakpoint at 768px width, you can input 767px and 768px to test layouts on both sides of the breakpoint.