Free online responsive design tester. Enter a URL to preview how it looks on mobile, tablet, laptop, and desktop screens. 100% client-side, nothing uploaded to any server.
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π Responsive Breakpoints Reference
| Breakpoint | Min Width | Target Device |
|---|---|---|
| xs | 0px | Small phones |
| sm | 576px | Large phones/Tablets |
| md | 768px | Tablets |
| lg | 992px | Small desktop/Laptop |
| xl | 1200px | Desktop monitor |
| xxl | 1400px | Large desktop |
Online Responsive Design Tester
Free online responsive design tester to help front-end developers and designers quickly check how websites render on different screen sizes. Supports multiple presets including phone, tablet, laptop, and desktop, as well as custom dimensions.
Why choose Responsive Design Tester
- Multi-device preview: One-click switch between Phone (375Γ667), iPhone 14 (390Γ844), iPad (768Γ1024), Laptop (1366Γ768), Desktop (1920Γ1080), and more
- Custom dimensions: Manually enter any width and height for precise resolution testing
- Orientation toggle: Rotate between landscape and portrait modes
- Quick loading: Enter a URL and click Load to preview instantly
Responsive Design Tester in 3 steps
Enter the URL you want to test in the input field (pre-filled with the Free ToolBase homepage), then click a device preset or adjust the width/height manually. The preview area resizes automatically. Click "Load" to refresh the preview. Some websites may not load due to X-Frame-Options restrictions β this is normal behavior.
FAQ
Can I use custom screen sizes?
Yes. Besides the presets for mobile/tablet/desktop, you can manually enter any width and height for custom testing.
Why can't some websites load in the iframe?
Some websites set X-Frame-Options: SAMEORIGIN or Content-Security-Policy headers that prevent loading in an iframe. This is the website's own security policy, not a problem with this tool.
Is my data secure?
Everything runs locally in your browser. The URL you enter is only used to load the preview and is not uploaded to any server.
Does it support landscape and portrait orientation?
Yes. Use the rotate button to switch between landscape and portrait orientation. The preview area adjusts automatically.