Responsive Testing Methodology

Testing at 3 device widths is insufficient. The responsive design must work at every width from 320px to 2560px — and the failures typically hide at non-standard widths that no device preset hits.

The testing methodology: automated viewport sweep from 320px to 2560px in 50px increments. At each increment, capture a screenshot and evaluate: layout integrity (no overlapping elements, no horizontal scrollbar, no cut-off content), typography legibility (no text below minimum size, no text exceeding maximum line length), spacing consistency (no elements touching screen edges, no collapsed gutters), and visual hierarchy (the primary content remains visually dominant at every width).

Manual testing supplements automation at critical widths: 375px (iPhone SE — the common minimum), 390px (iPhone 14/15), 768px (iPad portrait), 1024px (iPad landscape / small laptop), 1280px (standard laptop), 1440px (common desktop), 1920px (full HD), and 2560px (QHD/ultrawide). Manual testing catches interaction issues that screenshot-based automation misses: touch target sizes, scroll behavior, gesture conflicts.

Our testing cadence: full automated sweep runs on every deployment. Manual testing runs on every new page or significant layout change. Regression testing (automated screenshots compared to baseline) runs on every CSS modification.