Designing for Multiple Screen Sizes

Summary

Beyond breakpoints — accounting for the huge range of actual device sizes, aspect ratios, and pixel densities in the real world, not just 3 idealized viewport widths.

• 1Test a design on 2-3 genuinely different device sizes (not just a browser resize).
• 2Learn why designing for a few fixed sizes and letting flexible layout fill the gaps is more robust.
• 3Identify a real design that breaks on an unusual screen size or aspect ratio.