Responsive Web Preview
View webpage layout and rendering at phone, tablet, and desktop screen sizes.
What is responsive web preview?
A responsive web preview tool simulates common desktop, tablet, and mobile viewport sizes in one page. It helps you inspect navigation, text wrapping, image ratios, table overflow, and layout changes across screens. Enter a URL to load it in multiple iframes, switch to a single device view, or apply custom dimensions for frontend development, web design, and pre-release checks.
How to check responsive webpage layout
- Enter a complete http or https URL, click Load, and wait for the device iframes to finish.
- Use Compare all to inspect desktop, tablet, and mobile together, or View one to focus on a device.
- Choose a device, enter custom width and height, and click Apply to check special sizes or project breakpoints.
- Check menus, buttons, fonts, images, and horizontal scrolling with real content, then adjust CSS in your project.
Key benefits of responsive preview
Compare multiple devices
Desktop, tablet, and mobile pages appear together, making breakpoint-specific layout issues easier to spot.
Presets and custom dimensions
Common device presets are available alongside custom width and height for design specs, project breakpoints, and embedded containers.
Does not change the original page
The URL is displayed inside iframes. Resizing the preview changes only this tool’s viewport and does not write to site files or alter the live page.
Useful for pre-release checks
A quick pass through different viewports before a commit, campaign launch, or handoff can reduce missed mobile layout issues.
Responsive web preview frequently asked questions
Why does a URL fail to display?
The target may block iframe embedding with X-Frame-Options or Content-Security-Policy frame-ancestors, require login, block mixed content, or allow only selected origins. The tool cannot bypass browser security policies, so the site must permit embedding.
Does iframe width equal a real browser window?
The tool sets the iframe CSS width and height to inspect common responsive breakpoints. Browser chrome, device pixel ratio, fonts, and input methods can differ from real devices, so it complements rather than replaces device testing.
Does this tool upload my page?
The tool loads the URL in browser iframes and does not actively upload page source to a screenshot or analysis server. Images, fonts, APIs, and scripts referenced by the target page may still request their own resources.
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iframe Preview Tool
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