Responsive Design Tester

Preview any website across different device sizes. Test responsive layouts with popular presets or custom dimensions.

Website URL

Some sites may block iframe embedding. If a site doesn't load, it likely uses X-Frame-Options or CSP headers to prevent embedding.

View Mode

Quick Presets

Custom Dimensions

Enter a URL above and click Load to preview

1280 × 800

How It Works

This tool loads your website in an iframe at different viewport sizes to simulate how it appears on various devices. It helps identify responsive design issues without needing physical devices.

What It Tests

Viewport width and height — How your layout adapts to different screen sizes
Orientation — Portrait vs landscape behavior via the Rotate button
Multiple devices — Side-by-side comparison in multi-device mode
Custom dimensions — Test any arbitrary width and height

Common Responsive Breakpoints

Breakpoint	Width	Typical Devices
Extra small	< 576px	Small phones
Small	576 – 767px	Large phones
Medium	768 – 991px	Tablets
Large	992 – 1199px	Small laptops
Extra large	1200 – 1399px	Laptops, desktops
XXL	1400px+	Large desktops

Limitations

Sites that set X-Frame-Options or Content-Security-Policy frame-ancestors headers will not load in the iframe
This tool tests CSS viewport behavior, not actual device rendering (touch events, GPU, etc.)
JavaScript-based device detection on the target site will still detect your actual browser, not the emulated device

Embed This Util

You can embed this util on your own site as a widget. Adding ?embed=1 to the URL loads a compact version with just the tool itself; no header, menu, or documentation. Paste this snippet into your HTML:

Copy snippet Adjust the height to taste.

Feedback

Help us improve this page by providing feedback, and include your name/email if you want us to reach back. Thank you in advance.

Share with