Viewport Size Simulator
Emulate device screen sizes visually in the browser. Test responsive designs across different viewport dimensions.
Website URL
Device & Size
Mobile
Tablet
Desktop
⚠️ Website Loading Limitations
Some websites may not load due to security restrictions that prevent embedding in iframes (X-Frame-Options, Content-Security-Policy). This is a browser security feature that cannot be bypassed. If you own the website you're testing, you can temporarily disable these headers during development to use this tool.
Preview
About Viewport Size Simulator
A viewport size simulator is an essential web development tool that allows developers to test and preview how their websites appear across different device screen sizes and resolutions. This tool emulates various device viewports including mobile phones, tablets, desktops, and custom dimensions, helping ensure optimal responsive design implementation without needing physical devices.
Why use a Viewport Size Simulator?
Using a viewport size simulator streamlines responsive design testing, saves time and resources by eliminating the need for multiple physical devices, and ensures consistent user experience across all screen sizes. It helps identify layout issues, optimize media queries, and validate that your responsive design works properly before deployment, ultimately improving website accessibility and user satisfaction.
Who is it for?
This tool is perfect for web developers creating responsive websites, UI/UX designers testing interface layouts across devices, quality assurance testers validating cross-device compatibility, and digital agencies ensuring client websites work seamlessly on all screen sizes. It's also valuable for anyone involved in web development who needs to verify responsive design functionality.
How to use the tool
Enter the website URL or load your local development site
Select from preset device dimensions or enter custom width and height values
Click simulate to view how your website appears in the selected viewport size
Test multiple device sizes to ensure your responsive design works correctly
Use the tool to identify and fix any layout issues across different screen dimensions
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