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Viewport/Responsive Design Tester
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Test responsive designs
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What is Viewport/Responsive Design Tester?
Viewport Tester is a free online tool that allows you to test your website at different viewport sizes. Simulate mobile, tablet, and desktop screens to ensure your designs are responsive.
Features
- Test at custom viewport sizes
- Preset device sizes (iPhone, iPad, Desktop)
- Preview any URL in the viewport
- Fullscreen mode for better testing
- Real-time size adjustment
Frequently Asked Questions
Is this tool free to use?
Yes, Viewport/Responsive Design Tester is completely free. No registration required.
Is my data secure?
All processing happens in your browser. Your data never leaves your device.