Responsive Breakpoint Tester

Test websites at different screen widths and resolutions.

Input

Website URL: Width (px): Height (px):

Preview

What is the Responsive Breakpoint Tester?

The Responsive Breakpoint Tester allows developers to preview any website at custom screen widths and heights. It is ideal for testing responsive layouts, mobile breakpoints, tablet views and desktop scaling without needing browser devtools or external simulators. Simply enter a URL and choose a resolution to instantly see how the site behaves. All rendering happens client‑side inside an iframe, ensuring privacy and immediate performance. A fast and convenient tool for frontend developers, UI designers and QA testers.