Responsive Testing
Responsive testing verifies that a web page or app layout adapts correctly across different screen sizes and orientations — reflowing content, resizing elements, and hiding or showing components appropriately — rather than breaking, overflowing, or becoming unusable on smaller or larger viewports.
With responsive design, a single codebase serves phones, tablets, and desktops through CSS breakpoints and flexible layouts, rather than separate builds per device class — which means testing needs to check behavior across the range of breakpoints, not just at one fixed desktop resolution assumed to represent "the" experience.
Common responsive bugs cluster right at breakpoint boundaries — content that looks fine at 768px wide but breaks at 767px — which is why thorough responsive testing specifically targets the edges of each defined breakpoint, not just a handful of round, convenient screen sizes.
