Test how any website looks on different screen sizes and devices — desktop, laptop, tablet, and mobile. Preview your website's responsive design across 10+ device resolutions instantly, free online.
Enter a URL above and click "Preview Site" to see how it looks across devices.
Our free Responsive Website Checker lets you test any website across 8+ screen sizes and device types instantly. With Google's mobile-first indexing, ensuring your site looks and functions perfectly on every device is no longer optional — it directly impacts your search rankings.
In 2019, Google switched to mobile-first indexing — meaning Google primarily uses the mobile version of your website for indexing and ranking. By 2026, over 63% of all Google searches globally come from mobile devices. If your website doesn't render correctly on mobile, Google penalises your rankings regardless of how good your desktop experience is.
max-width: 100% for all images.<meta name="viewport">, mobile browsers render at desktop width.