Responsive Website Tester: Live Multi-Device Screen Preview

Test and optimize your website's responsiveness effortlessly across all screen sizes. Our online responsive design viewer allows developers, designers, and site owners to preview any web page on popular mobile, tablet, and desktop device presets—or enter custom viewport dimensions. Equipped with device orientation toggle (portrait/landscape), full-screen inspection mode, instant page refresh, and local history tracking, you can quickly spot layout bugs, test breakpoint behaviors, and deliver flawless cross-device user experiences without leaving your browser.