📱 Responsive Webpage Multiviewer
Test website layouts across Mobile, Tablet, and Desktop viewports side-by-side in real-time. Toggle orientation, input live URLs, or test custom HTML. 100% free.
❓ Frequently Asked Questions
Why do some external websites fail to load inside the preview frames?
Some websites enforce security headers (such as X-Frame-Options or Content-Security-Policy) that prevent their pages from being embedded in third-party iframes. For local testing or custom layout checks, you can switch to Custom HTML Sandbox mode.
What standard device screen sizes are tested in the multiviewer?
The multiviewer defaults to standard responsive breakpoints: Mobile Portrait (375px × 667px), Tablet Portrait (768px × 1024px), and Desktop (1280px × 800px).
Is my URL or tested HTML code uploaded to external servers?
No. All URL framing, orientation calculations, and HTML sandbox renders operate 100% locally inside your web browser.
