Responsive Test
URL to test
Many sites block iframe embedding (X-Frame-Options or CSP headers). In that case, the iframe will appear empty.
Previews
Mobile 375px
Tablet 768px
Desktop 1280px
How does it work?
The tool loads the given URL in three iframes at different widths: 375px (mobile iPhone), 768px (tablet) and 1280px (desktop). You can quickly compare rendering without opening devtools.
Limits
Many modern sites block iframe embedding via X-Frame-Options or Content-Security-Policy headers. In that case, the browser refuses to display the page and the iframe appears empty. Notable examples include Google, Facebook, Twitter, etc.